All action alternatives include a version of the classifications^[6] of the Merced River corridor revised from those published in the 1996 Draft Yosemite Valley Housing Plan.

The classifications (wild, scenic, or recreational) for the various segments are based on existing conditions observed in the river corridor. As shown in figure II-3, the classifications for all segments of the river corridor are the same across the alternatives (including the No Action Alternative), with some exceptions in Yosemite Valley and Wawona. In Alternatives 2, 4, and 5, east Yosemite Valley (Nevada Fall to Sentinel Beach) and Wawona are classified as "recreational"; these segments are classified "scenic" in Alternatives 1 and 3. This does not necessarily mean that these segments are to be managed differently than if they were classified as "scenic." Rather, the recreational classification reflects the current extent of developed areas and facilities in these segments. When the river corridor boundary is expanded to include the full quarter-mile, as it is with Alternatives 2, 4, and 5, then the corridor encompasses more areas and more intensive uses and therefore necessitates a "recreational" classification as defined by the Wild and Scenic Rivers Act. However, the scenic classification would require the National Park Service to limit development in the river corridor to a level compatible with this classification.

In addition, all alternatives allow for the removal of the Cascades Diversion Dam and the Wawona Impoundment. If either of these structures were removed, the classifications of the segments would be changed to reflect surrounding classifications (e.g., from "recreational" to "scenic").

Revised Outstandingly Remarkable Values

Outstandingly Remarkable Values (ORVs) are defined by the Wild and Scenic Rivers Act as those characteristics that make the river worthy of special protection. These can include scenery, recreation, fish and wildlife, geology, history, culture, and other similar values, which are to be considered in determining eligibility for Wild and Scenic River designation. ORVs are typically identified in a study prior to the designation of a Wild and Scenic River.

The first documentation of the Merced River's Outstandingly Remarkable Values relative to the Wild and Scenic Rivers Act occurred with the 1982 National Rivers Inventory conducted by the National Park Service. Subsequent listing of the Merced River's values, which qualified the river for inclusion in the Wild and Scenic Rivers System, occurred during the interdisciplinary study which became part of the 1986 Sierra National Forest Draft Forest Land and Resource Management Plan. This plan recommended the river for designation as a Wild and Scenic River. Congressional committee reports to the House of Representatives and Senate regarding the authorization bill (H.R. 317) contained brief descriptions of the ORVs along with the concern that a proposed hydroelectric project on the river just outside Yosemite National Park threatened the values that qualified it for inclusion in the system.

The National Park Service initially published ORVs for the Merced River corridor in the 1996 Draft Yosemite Valley Housing Plan. These 1996 ORVs are included in the No Action Alternative and are part of the existing management direction for the Merced River corridor. The 1996 ORVs and a description of how these have been revised are provided in Appendix E.

As part of the development of the Merced River Plan/FEIS, the 1996 version of the ORVs has been refined. This revision is based on the application of new scientific information, changed ecological and hydrologic conditions in the river corridor, and to accurately reflect ORV criteria developed by the Interagency Coordinating Council in its guidelines for implementation of the Wild and Scenic Rivers Act. Two vital questions establish the criteria for selection of ORVs:

• Is the value river-related or river-dependent?

• Is the value rare, unique, or exemplary in a regional or national context?

Both of the above criteria must be satisfied in order for a characteristic to be included as an ORV. To comply with the Wild and Scenic Rivers Act, all of the action alternatives protect and restore the same set of revised ORVs. The following are the categories of ORVs used in the Merced River Plan/FEIS (table II-1 presents the ORVs for each river segment):

This section provides a narrative description of the revised ORVs illustrated in figure II-4 and detailed in table II-1.

The Merced River flows westward from the peaks of the Sierra Nevada through mountain valleys and steep gorges until it joins the San Joaquin River in the San Joaquin Valley. The Merced River corridor is host to a diversity of natural communities, such as meadows, forests, lakes, and wetlands, along with the wildlife species that depend on them. Running for much of its length through Yosemite National Park, including significant portions in designated Wilderness, the Merced River is one of few major rivers draining the Sierra Nevada that has largely remained free-flowing in its upper reaches.^[7] The Merced River corridor also bears the traces of thousands of years of human habitation and serves as an important link to Yosemite's cultural heritage. Today, the Merced River corridor provides a key setting for scenic, recreational, and educational experiences for visitors to Yosemite National Park.

Above the treeline, the Merced River flows through granitic bedrock in the Clark and Cathedral Ranges. The river travels toward Little Yosemite Valley through a glaciated, U-shaped canyon that drops precipitously from 13,000 to 6,000 feet in elevation in a channel unaltered by human intervention. The river corridor contains alpine and subalpine lakes, dramatic waterfalls and cascades, and offers panoramic views of the granite domes and peaks of the surrounding mountains. Given its remote location and protected status as a Wilderness area, this section of the Merced River corridor contains most of the riverine vegetation and wildlife typical of the alpine and subalpine environment. Visitors can enjoy solitude as well as wilderness hiking, stock packing, and camping. The area was part of a major prehistoric trans-Sierra route and contains numerous prehistoric archeological sites as well as several historic structures associated with early settlement and tourism.

Weaving through Yosemite Valley, the Merced River corridor is central to many of the renowned views of Yosemite National Park. These include granite domes and cliffs such as Half Dome, North Dome, and Sentinel Dome; waterfalls such as Vernal, Yosemite, Sentinel, and Bridalveil; and Stoneman, Sentinel, Bridalveil, and other meadows. The glaciated, flat-bottomed valley starting below Happy Isles is an example of a mature, meandering river with an active flood cycle and associated oxbows, wetlands, and riparian vegetation.

There is evidence of glaciation, including hanging valleys at Yosemite and Bridalveil Creeks. The ribbon of vegetation along the Merced River corridor and its associated wetlands and meadows provide rich habitat for many species of river-associated plants and wildlife, including neotropical migrant songbirds and numerous species of bats. This pattern of open meadow along the river is a component of the cultural landscape as well, contributing to the historic character of Yosemite Valley that dates from Indian occupation to the present. American Indians have used the valley and the river corridor. There are many significant river-related archeological sites here, some of which contain important evidence of cultural contact and change. Yosemite Valley is also proposed for listing as a nationally significant cultural landscape, representing a pattern of human land use that has evolved for thousands of years. This landscape reflects adaptation from American Indian homeland, Euro-American homesteading, development of tourism, birthplace of the national conservation movement, and finally, National Park Service ideals for landscape architecture. Visitors to the corridor can enjoy numerous river-related recreational experiences, including hiking, swimming, sightseeing, and nature study.

The segment of the river corridor surrounding the remains of the Cascades Diversion Dam is at the dramatic transition from the flat-bottomed, glaciated Yosemite Valley to the V-shaped river gorge. Riparian vegetation provides habitat for a variety of riverine species.

Beginning below the Cascades Diversion Dam and continuing downstream to the western park boundary at El Portal, the Merced River rushes down an exceptionally steep gradient through a V-shaped, river-carved gorge. Visitors can enjoy views of the Cascades, Wildcat Fall, Tamarack Creek Fall, spectacular rapids among giant boulders, the Rostrum, and Elephant Rock from the river and its banks. Because of the relatively inaccessible location, the riparian communities, while narrow, are largely intact and almost entirely undisturbed. There are several archeological sites and at least one important ethnographic property in the Cascades area, and many historic resources associated with early engineering projects. Visitors can find access to river-related recreational opportunities such as picnicking, sightseeing, swimming, nature study, and photography.

The Merced River leaves Yosemite National Park and enters the El Portal Administrative Site at the park's western boundary, where the underlying rock begins a shift from granitic to metasedimentary. The river's continuous rapids provide kayaking and white-water rafting opportunities (class III to V). Riparian forests, especially dense on the south side of the river, provide important plant and wildlife habitat. River-related special-status species, such as Valley elderberry longhorn beetle and Tompkin's sedge, can be found along the river corridor. This stretch of the corridor contains numerous river-related archeological and historical sites, such as American Indian settlements, cemeteries, and historic structures related to early tourism and industrial development.

The South Fork of the Merced River originates among the peaks of the Clark Range, on the south side of the Merced River watershed divide, and flows through high alpine meadows and forests. Views of the pothole pools within slick rock cascades, old growth forests and meadows, remote expanses without trails, and significant opportunities for solitude and enjoyment of natural river sounds make this an outstanding example of the Sierra Nevada wilderness experience. The river drops from alpine and subalpine zones through distinct meadow areas, old growth forests, and rugged riverine environments. Varied trail opportunities and swimming holes provide recreational attractions. Like the wilderness on the main stem of the Merced River, this reach contains nearly the full range of riverine habitats and vegetation types of the central Sierra Nevada. Wawona riffle beetles and the mountain yellow-legged frogs are among the special-status species found in this area. Cultural resources include significant historic cabins and campsites, precontact and historic archeological sites, and historic trails associated with early exploration and mining enterprises in the 19th century.

The river corridor surrounding the Wawona Impoundment is marked by excellent water quality and provides views from the river and its banks of the Wawona Dome and the river itself.

As the Merced River enters the Wawona area, it flattens out to a gentler gradient with a broader floodplain of rocky cobbles. There are clear views of Wawona Dome, and species such as the protected Wawona riffle beetle are found in the river corridor's wetlands and riparian habitats. Cultural resources along the river corridor through Wawona include both precontact and historic archeological sites, settlement and homestead sites, 19th century resort development, and National Park Service historic structures.

Downstream of Wawona, the Merced River flows in a steep gradient through a narrow, V-shaped canyon that exposes the transition from granitic to a metasedimentary underlying rock. The slopes are blanketed by largely intact coniferous and riparian deciduous forest. Continuous runs of rapids and numerous cascades make this a challenging white-water kayaking site, popular among expert kayakers. Visitors may also enjoy river-related hiking, nature study, and swimming opportunities. Largely inaccessible stretches of the river corridor offer opportunities for solitude and enjoyment of natural river sounds. Protected species such as the Wawona riffle beetle inhabit this area. Archeological sites and historic trail segments are located here.

Section 7 Determination Process

"Water resources projects," that is, those that are within the bed or banks of the Merced River and therefore affect the river's free-flowing condition, are subject to Section 7 of the Wild and Scenic Rivers Act (16 USC 1278).^[8] As the designated "river manager" for the Merced River for the segments addressed by this Merced River Plan/FEIS, the National Park Service must carry out a Section 7 determination on all proposed water resources projects to ensure that they do not directly and adversely impact the values for which the river was designated.^[9]

The National Park Service is responsible for making the final determination as to whether a proposed water resources project will have a direct and adverse impact to the values for which the river was designated Wild and Scenic. The agency should coordinate its evaluation process with other agencies that are required to review and comment on the project. Depending on the type and location of the project, this may include the U.S. Fish and Wildlife Service, the Environmental Protection Agency, the U.S. Forest Service, the Bureau of Land Management, and the U.S. Army Corps of Engineers. Review of Section 7 projects would also be coordinated with other environmental review processes, such as those required by the National Environmental Policy Act and the National Historic Preservation Act, as appropriate.

The National Park Service would undertake the following steps as part of its Section 7 determination process for nonemergency projects. In emergency situations (e.g., a broken sewer pipe in or near the river), a Section 7 determination must be carried out as soon as possible after the project is completed. Changes to mitigate impacts from an emergency project should be implemented, when necessary, based on the findings of the Section 7 analysis.

1. The National Park Service would describe the purpose and need of the proposed project, its location, duration, magnitude, and relationship to past and future management activities.

2. The National Park Service would analyze the potential impacts of the proposed project on the values for which the river was designated. This analysis should follow the guidelines provided by the Wild and Scenic Rivers Act, Section 7 Technical Report of the Interagency Wild and Scenic Rivers Coordinating Council (1999) and other applicable guidance.

3. The National Park Service would define the likely duration of the projected impacts.

4. The National Park Service would assess the effects of the projected impacts on the achievement or timing of achievement of the management goals of the Merced River Plan (based on the Wild and Scenic Rivers Act).

5. The National Park Service would use this analysis to make a Section 7 determination. This determination would document the effects of the proposed activity, including any direct and adverse effects on the values for which the river was designated.

6. Projects determined to cause direct and adverse impacts to the values for which the river was designated could be redesigned and resubmitted for a subsequent Section 7 determination. Projects that could not be redesigned would either be abandoned or could proceed following notification, in writing, of the Secretary of the Interior and the United States Congress in accordance with Section 7(a) of the act.

7. The National Park Service would also follow Section 7 procedures to determine if projects above or below the designated river or on its tributary streams would invade the area or unreasonably diminish the scenic, recreational, and fish and wildlife values present in the designated corridor.

River Protection Overlay

The areas immediately adjacent to the river channel, along with the river channel itself, are particularly important to the health and proper functioning of the river ecosystem. These areas allow for the main channel to link with backwater areas, tributaries, and groundwater systems; provide for increased channel diversity; and contribute sources of needed nutrients and woody debris to the river.^[10] Additionally, they can help protect surrounding development from potential flood damage and can be used to filter runoff water draining into the river.

To ensure that the river channel itself and the areas immediately adjacent to the river are protected, every action alternative, except Alternative 5, includes a management tool called the River Protection Overlay (RPO). The RPO would provide a buffer area for natural flood flows, channel formation, riparian vegetation, and wildlife habitat and would protect riverbanks from human-caused impacts and associated erosion. The RPO is intended to apply the requirements of the Wild and Scenic Rivers Act, including the protection and enhancement of the Outstandingly Remarkable Values (ORVs) and the preservation of the free-flowing condition of the river, at a higher standard than that of the underlying management zones. It is intended as a primary mechanism to achieve the goals of the Merced River Plan. The RPO is also intended to be the location of highest priority for restoration of hydrologic processes and biotic habitats within the river corridor.

Projects occurring within the bed or banks^[11] of the river and that affect the free-flowing condition of the river are considered "water resources projects" under the Wild and Scenic Rivers Act, and must go through a Section 7 determination process.

Within the River Protection Overlay, future actions shall be consistent with the following conditions:

1. Nonessential facilities (including, but not limited to, riprap, levees, diversion walls, impoundments, bridges, bridge abutments, roads, campsites, buildings, utilities, and other structures) should not be located in the RPO, except when they meet the following two criteria: (1) where required for access to or across the river, for health and safety, or for the maintenance of historic properties; and (2) where it is impractical to locate them outside the RPO.

   • Existing facilities meeting these criteria may remain, and they may be replaced, repaired, or relocated within the RPO, but only if the replacement, repair, or relocation does not directly and adversely affect the ORVs.

   • New facilities and development may be constructed in the RPO only when meeting these criteria and when located where they do not materially impair the natural function of the river, impede linkages to tributary inflow and backwater areas, or disrupt contribution of woody debris to the river, and where they do not have a direct and adverse impact on the ORVs.

2. Actions to construct, replace, repair, or relocate essential facilities (i.e., primary roads and bridges, wastewater collection and treatment, domestic water supply, electrical distribution, and similar facilities required to keep the park open) and facilities that directly protect and enhance the ORVs (e.g., raft launch facilities to preserve the spectrum of recreational experiences and to concentrate use in a hardened area), within the bed and banks of the river, may be permitted provided that:

   • Project design minimizes impacts to the free-flowing condition of the river, interference with linkages to tributary inflow and backwater areas, and disruption of contribution of woody debris to the river.

   • The project incorporates mitigation measures to avoid or reduce impacts.

3. Facilities and development covered by paragraphs 1 or 2, above, that occur within the bed or banks of the river and that affect the free-flowing condition of the river must also comply with Section 7 of the Wild and Scenic Rivers Act.

4. Other existing facilities that are not addressed by paragraphs 1 or 2 should be removed and must be removed, at the earliest practicable opportunity, when major rehabilitation is needed or when a facility is no longer of use.

The specific areas included with the River Protection Overlay may shift over time to follow the movement of the river channel itself. The width of the River Protection Overlay is determined by site topography and vegetation and includes the area needed to encompass riparian and adjacent upland vegetation and habitat.^[12] The River Protection Overlay, in areas above 3,800 feet, includes the river channel itself and extends 150 feet on both sides of the river measured from the ordinary high water mark; and in areas below 3,800 feet includes 100 feet on both sides of the river measured from the ordinary high water mark. Generally, a wider band is required along the river in the flatter, open valleys, while a narrower buffer provides adequate protection in the steeper, V-shaped river gorges of the lower elevations (see figure II-5). This transition occurs approximately at the 3,800-foot elevation mark, in the gorge area below Yosemite Valley on the main stem of the Merced River, and downstream of Wawona on the South Fork. Approximately 70 miles of the river would have a 150-foot River Protection Overlay, including Yosemite Valley and Wawona. Approximately 11 miles of the river would have a 100-foot River Protection Overlay, including the El Portal Administrative Site.

Management Zoning Prescriptions

This section defines the management zones used for the Merced River corridor. Management zoning is a technique used by the National Park Service to classify park areas and prescribe future desired resource conditions, visitor activities, and facilities. A management zone is defined in the National Park Service's Visitor Experience and Resource Protection (VERP) framework as:

The zoning seeks to protect and enhance the Outstandingly Remarkable Values of the Merced River corridor. Management zoning is one of the elements in the Merced River Plan/FEIS that helps protect and enhance ORVs. Management zoning prescribes certain uses and facilities that are not allowed in an area. In the absence of zoning, additional development and higher-intensity uses could impact ORVs over the long term. Management zoning also provides opportunities for restoration of ORVs in areas where lower use and facility levels are prescribed. Management zoning protects the spectrum of recreational opportunities (an ORV) by allowing for visitor access and use of facilities in more resilient locations, and different intensities of use along the corridor.

Zones are represented schematically on the alternatives maps. Implementation of the management zones will require additional mapping and site-specific studies.

The management zones for the Merced River corridor fall into three general categories: (1) Wilderness zones, (2) Diverse Visitor Experience zones, and (3) Developed zones. For each of these three categories, there are individual management zones that provide for certain levels and types of visitor experiences, resource conditions, facilities, and uses. Existing uses or facilities that are not compatible with the management prescriptions of their zones could be removed, relocated, or modified over time. Management zones generally allow for the repair, maintenance, and reconstruction of established facilities (such as structures, utilities, roads, and bridges) unless specifically noted. All zones also allow for scientific research and monitoring activities, particularly related to the analysis of visitor experience and resource protection of the river corridor.

The management zones are organized along a continuum of allowed impact intensity. Category 1 zones (Wilderness) generally prescribe the least amount and intensity of visitor use and facility development, leaving the landscape mostly natural and protecting the values reflected in the wilderness segment ORVs. Category 2 zones (Diverse Visitor Experience) allow for a low to high range of visitor use and low to moderate range of facility development. While emphasizing protection and enhancement of natural and cultural resource-related ORVs, they provide the diverse recreational opportunities also identified as ORVs. Category 3 zones (Developed) occur in limited areas in scenic and recreational segments. These zones allow for the most intensive visitor use and/or more developed facilities. The developed areas encourage concentration of higher-impact activities in areas better able to withstand heavy use and at locations that are already developed, enabling better protection of ORVs in other areas. Within each broad zoning category, the level of intensity that is allowed generally increases as the specific zones progress (e.g., 2A to 2B to 2C). There are certain exceptions to this hierarchy. For example, the Attraction Zone (2D) may envision higher use levels than the Camping Zone (3A).

Zoning prescriptions list typical activities, allowed facilities, and examples of facilities not allowed in each zone. These lists are not exhaustive. In general, the more intensive facilities allowed for in higher category zones would not be allowed in the lower category zones. For example, administrative offices are allowed in Category 3 zones, but not in Category 1 or 2 zones. When determining whether a specific use or facility is appropriate to a management zone, park managers should consider the general character of development and desired resource and visitor experience conditions described for that zone.

The River Protection Overlay is applied over the zoning categories throughout the length of the river corridor in all action alternatives, except Alternative 5. In all cases, where the management prescription and the River Protection Overlay are in conflict, the prescription that provides the greater protection and enhancement of the ORVs takes precedence.

Each zone prescribes the maximum level of activities and facilities. In practice, lower levels of visitor use and facilities may be provided than are allowed for in the zoning prescriptions. Typical uses in lower-intensity zones are generally acceptable uses for higher-intensity zones. For example, areas zoned for overnight lodging may be used for less-developed activities such as walk-in camping or could include protected natural areas. These decisions would be based on site-specific conditions as assessed through routine management activities. The zones, delineated conceptually on the alternatives maps, are also fairly broad in order to allow future managers to direct development within the zone. Within a given zone, there may be some areas used for higher-intensity facilities or activities, while other areas within the same zone are left natural and open.^[13]

Uses or activities allowed in a management zone may be subject to limitations over time. If ongoing monitoring (as implemented through the VERP framework) indicates that impacts on the resource or visitor experience are no longer at an acceptable level, previously designated areas may be further restricted. Management zone prescriptions can also be temporarily superceded by contingencies, such as the need to respond to emergencies. For example, trails, roads, and facilities may be temporarily closed because of fire, rockfall, or flood.

An area may be designated with two management zones; there are two instances in which multiple zoning is used. The first is where a site may be used for multiple, compatible purposes.^[14] In Alternative 2, the Yellow Pine Campground in Yosemite Valley is zoned 3A/3C for Camping and Park Operations. This area is currently used as a camping area for park volunteers (an administrative use) and could, in the future, be used as a combination of volunteer and visitor camping or solely as visitor camping.

The second case is where a zoning designation may change in the future ^[15] depending on specific management actions. For example, the Arch Rock Entrance Station is zoned 3C(2C) for Park Operations/Administration or Day Use in all alternatives. This area is currently used for park operations, but if the entrance station were relocated in the future, the area would convert to Day Use, which would allow for various visitor activities such as picnicking.

The management zones of the Merced River Plan/FEIS are consistent with the purposes of Yosemite National Park, the Wild and Scenic Rivers Act, and the Wilderness Act. The Merced River Plan provides equal, and in some cases greater protection for ORVs than the zones in the General Management Plan and meets the requirements for Wilderness areas under the Wilderness Act.^[16]

Approximately 34 miles of the main stem and 19 miles of the South Fork of the Merced Wild and Scenic River corridors flow through designated Wilderness and are managed under the guidance and requirements of the 1964 Wilderness Act and the California Wilderness Act of 1984. As such, these segments will continue to be managed to preserve an environment in which the natural world, along with the processes and events that shape it, are largely unchanged by human use, and to allow for various forms of exploration in an environment primarily free of modification. Access limits are imposed to control human-induced change, and management actions such as education, regulation, and restoration will occur as appropriate to protect natural and cultural resources and designated ORVs. Visitor use and enjoyment is encouraged as long as such use does not result in levels of human impact that compromise wilderness and river values. Visitors would encounter a variety of opportunities for solitude, primitive and unconfined recreation, and physical challenge. Presence of park staff would be limited, focused on locations of heavy use such as camping areas.

The Wilderness zones would be managed to protect the natural hydrologic and ecologic processes of the Merced River and its immediate environment. Other than trails and designated overnight areas, the Wilderness zones would exhibit natural conditions, with high-quality riparian, meadow, and aquatic habitats. There would be high native plant and animal species diversity and relatively minimal disturbance and human impact. The Merced River would remain free of impoundments, and natural processes, such as deposits of woody debris into the river, would occur without human interference. Water quality in the area would be very high.

The Wilderness zones emphasize the protection of natural resource ORVs, such as biological, geologic, and hydrologic values. By limiting use and development, the Wilderness zones also protect and enhance cultural, scenic, and recreational ORVs, which identify spectacular views, prehistoric sites, and opportunities for solitude and primitive recreation among the important values of the wilderness segments of the Merced River corridor.

There are four Wilderness zones:

• Zone 1A: Untrailed

• Zone 1B: Trailed Travel

• Zone 1C: Heavy Use Trail

• Zone 1D: Designated Overnight

The overall management objectives for the Wilderness zones are as follows:^[17]

• Manage for protection of Outstandingly Remarkable Values, with an emphasis on protection and enhancement of natural resource ORVs

• Manage for ecosystem integrity

• Preserve natural biodiversity

• Allow natural processes to prevail

• Mitigate, reduce, or eliminate human-caused impacts

• Manage for a high-quality wilderness visitor experience

• Protect all wilderness values (ecological, geological, scientific, educational, scenic, or historical in nature)

• Apply the "minimum requirement" guidance concept in all administrative operational functions in accordance with the Wilderness Act

• Manage for the preservation of cultural resources

The Untrailed zone would be primarily free of signs of modern human presence, with extremely high opportunity for solitude due to the remoteness of the area and lack of trails. Management activities in this zone would be minimal, allowing resources and natural processes to exist in their most pristine state. The Untrailed zone would be managed with very low tolerance for resource degradation from visitor use, and management action could be taken to change visitor use patterns if such degradation occurred.

Visitor experience would be primarily based on hiking through often difficult terrain. There would be no formal trails or directional markers in this zone. There would be few, if any, human encounters, and wilderness skills and knowledge could be necessary to safely navigate these areas. Natural and cultural resources could be observed, but there would be no formal interpretation or visitor accommodations. This area would provide substantial opportunities for scientific study of natural processes in undisturbed conditions.

The difficulty of access characterized by the Untrailed zone would serve to reduce visitor use, thereby protecting and enhancing biological, geologic, hydrologic, cultural, scenic, and scientific ORVs. Opportunities for solitude, primitive and unconfined recreation, and enjoyment of natural river sounds are among the recreational ORVs prominent in this zone.

Activities – The following activities would be typical in this zone:

• Overnight camping 100 feet or more from a water body, by permit

• Hiking

• Rock climbing and mountaineering

• Swimming and wading

• Fishing^[18]

• Photography and nature study

Facilities – The following facilities would be allowed in this zone:

• Limited numbers of legal and appropriately dispersed campsites

The following are examples of facilities that would not be allowed in this zone:

• Support facilities such as food storage, ranger stations, and compost toilets

• Utilities

• Bridges

• Formal trails

• Interpretive signs or programs

• Commercial overnight facilities

The Trailed Travel zone would be characterized by light to moderate use focused on marked and maintained trails. Opportunities for solitude would range from moderate to high. There would be some management presence to accommodate resource protection and visitor use. The Trailed Travel zone would be managed with very low tolerance for resource degradation from visitor use, and management action could be taken to change visitor use patterns if such degradation occurred.

Most visitors would experience this area by hiking, although a small percentage of visitors have traditionally used pack animals and could continue to do so. Visitor encounters would be infrequent, except in areas common for campsites and at key trail junctions. While there would be opportunities for challenge and adventure, the well-marked and maintained trails would allow visitors with a diversity of hiking abilities to experience the wilderness.

Through limitations on development and access, the Trailed Travel zone would protect and enhance biological, geologic, hydrologic, cultural, scenic, and scientific ORVs. Opportunities for solitude, primitive and unconfined recreation, and enjoyment of natural river sounds are among the recreational ORVs prominent in this zone.

Activities – The following activities would be typical in this zone:

• Overnight camping 100 feet or more from a water body or trail, by permit

• Hiking

• Rock climbing and mountaineering

• Stock use as allowed in the Wilderness Management Plan

• Swimming and wading

• Fishing

• Photography and nature study

• Very limited interpretive programs (e.g., guided walks for small groups)

Facilities – The following facilities would be allowed in this zone:

• Marked and maintained trails (walls and water bars could be used to provide for protection of resources)

• Limited numbers of legal and appropriately dispersed campsites

• Historic features

• Occasional directional and regulatory signs, and safety signs only as necessary

• Footbridges only at trail crossings where necessary for resource protection and visitor access (in compliance with the Wilderness Management Plan)

The following are examples of facilities that would not be allowed in this zone:

• Large campsites with facilities

• Commercial overnight facilities

• Utilities

The Heavy Use Trail zone would be characterized by high levels of use on marked and maintained trails and associated areas. Due to high use levels, opportunities for solitude at peak times would be more limited on trails in this area. In some locations, sections of paved or rocked trails and fencing could be used to direct visitor use away from sensitive ecosystems. The Heavy Use Trail zone would be managed with a low tolerance for resource degradation due to visitor use, and management action could be taken to redirect use if such degradation occurred.

Most visitors would experience this area by hiking, although a small percentage of visitors have traditionally used pack animals and could continue to do so. Encounters with other visitors could be frequent during certain periods of the day or at key trail junctions, vistas, and other high use locations. The well-marked and maintained trails would allow for visitors with a diversity of hiking abilities to experience the wilderness.

Through limitations on development, the Heavy Use Trail zone would protect and enhance biological, geologic, hydrologic, cultural, scenic, and scientific ORVs. While opportunities for solitude would be lower than in the less-traveled Untrailed and Trailed Travel zones, this zone would provide ready access to wilderness hiking and backpacking near the Merced River.

Activities – The following activities would be typical in this zone:

• Hiking

• Rock climbing and mountaineering

• Stock use as allowed in the Wilderness Management Plan

• Photography and nature study

• Swimming and wading

• Fishing

• Very limited interpretive programs (e.g., guided walks for small groups)

Facilities – The following facilities would be allowed in this zone:

• Marked and maintained trails. (Some trails could have remnant paving, soil amendments, hardened surfaces. Stairs, walls, fencing, and other trail features could be constructed for visitor use management and protection of sensitive areas.)

• Directional, regulatory, and safety signs

• Footbridges only at trail crossings where necessary for resource protection and visitor access (in compliance with the Wilderness Management Plan)

The following are examples of facilities that would not be allowed in this zone:

• Campsites

• Commercial overnight facilities

The Designated Overnight zone would be characterized by the heaviest overnight use of all areas of the Wilderness zones. Designated overnight areas would be centered at destination locations with facilities for resource protection and visitor use, specifically at the Little Yosemite Valley Campground, Moraine Dome Campground, Merced Lake Campground, and the Merced Lake High Sierra Camp (a potential Wilderness addition). Opportunities for solitude would range from low to moderate depending on the season. Social interaction would be common. Presence of National Park Service staff would be moderate to high in order to prevent or mitigate most adverse impacts. The Designated Overnight zone would be managed with a low tolerance for resource degradation due to visitor use. Facilities such as signs and fencing could be used to prevent unacceptable impacts. Campsites would be located away from any sensitive natural or cultural areas, including meadows, streams, lakes, and historic and archeological sites, to minimize impacts.

Most visitors would experience this area by hiking and/or staying overnight. Small percentages use pack animals and could continue to do so. Visitor encounters with others would be frequent during much of the hiking seasons. The well-marked trails and facilities would allow for a diversity of users to experience the wilderness.

The Designated Overnight zone concentrates visitor facilities in a localized area, allowing for higher protection and enhancement of biological, geologic, hydrologic, cultural, scenic, and scientific ORVs outside this zone. This zone also ensures that historic structures such as the High Sierra Camp could remain for continued use or for interpretive purposes. Signs, fencing, and other features could be used to direct visitors away from sensitive biological and cultural ORVs, as necessary.

Activities – The following activities would be typical in this zone:

• Overnight camping only within a campground setting, by permit

• Hiking

• Wilderness skiing

• Photography and nature study

• Very limited interpretive programs (e.g., occasional ranger talks, guided walks)

• Stock use as allowed in the Wilderness Management Plan

• Use of High Sierra Camps as allowed in the Wilderness Management Plan

Facilities – The following facilities would be allowed in this zone:

• High Sierra Camps as allowed in the Wilderness Management Plan

• Designated campsites of moderate size

• Food storage and campfires, subject to regulation

• Compost toilets and toilet enclosures (as necessary to protect resources)

• Structures such as the Little Yosemite Valley Campground and Ranger Station, Merced Lake Campground, and Merced Lake High Sierra Camp (to concentrate use and reduce or mitigate ecosystem degradation, or for interpretation as a cultural resource)^[19]

• Marked and maintained trails. (Some trails could have remnant paving, soil amendments, or hardened surfaces. Stairs, walls, fencing, and other trail features could be constructed for visitor use management and protection of sensitive areas.)

• Directional, safety, informational, and regulatory signs, and minimal interpretive signs when required for protection of resources

• Utilities associated with above facilities

The following are examples of facilities that would not be allowed in this zone:

• New commercial overnight facilities

• Campsites outside of designated areas

The Merced River corridor serves as an important recreational resource, providing opportunities for nature study, hiking, picnicking, swimming, fishing, and other activities for many of the 4 million people who visit Yosemite National Park each year. The Merced River corridor also serves as a continuous visual element of the landscape, setting off significant features such as waterfalls, granite domes, and peaks.

Natural resource management in these zones would strive to protect and enhance the natural functioning of ecological and hydrological systems while accommodating moderate levels of visitor use. The Category 2 zones are designed to protect and enhance biological, hydrologic, geologic, scenic, cultural, and scientific ORVs, as well as the recreational ORVs. This would be achieved by maintaining, wherever possible, the integrity of an overall ecological unit (such as a meadow, woodland, or wetland), while allowing for some human alteration of the landscape. Riparian, aquatic, and meadow communities in the river corridor play a particularly critical role in a variety of ecosystem processes and are also contributing cultural landscape resources. Restoration of the ecological and hydrological systems in these areas would focus on enhancing the diversity and stability of natural functions. Resource degradation would be minimized by the careful design and siting of facilities that direct visitor and administrative activities to locations able to withstand heavy use. Monitoring of visitor impacts on natural and cultural resources would help ensure adaptive and timely management responses to potential resource degradation.

The Diverse Visitor Experience zones would be managed to protect and enhance the hydrologic and ecologic processes of the Merced River and its immediate environment. Riparian areas and meadows should remain largely intact, supporting a diversity of native vegetation and wildlife species. However, localized areas could be developed with trails, roads, and parking areas and a greater amount of resource protection features (e.g., fencing and boardwalks) to allow for visitor access. Higher levels of resource impacts (e.g., trampling and soil erosion) and a greater amount of resource protection features might be expected in limited areas within the Day Use and Attraction zones to accommodate high numbers of visitors. The free flow of the river would remain primarily unimpeded. Water quality in the area should be of high quality.

The Diverse Visitor Experience zones protect cultural ORVs such as historic structures and prehistoric sites by directing visitor access to areas able to withstand heavy use. Restoration of natural features such as wetlands and meadows would also restore the cultural landscape. Interpretation of historic resources is allowed in these zones to provide visitor education opportunities.

The Category 2 zones also protect and enhance recreational ORVs, which emphasize the value of providing diverse recreational opportunities for visitors. The lower-intensity zones, Open Space and Discovery, provide opportunities for quiet enjoyment of the river corridor, while the Day Use and Attraction zones accommodate higher levels of use at park destinations.

Four management zones are defined for the Diverse Visitor Experience zone category:

• Zone 2A: Open Space (and Undeveloped Open Space)

• Zone 2B: Discovery

• Zone 2C: Day Use

• Zone 2D: Attraction

The overall management objectives for the Diverse Visitor Experience zones are:

• Manage for protection, enhancement, and restoration of Outstandingly Remarkable Values, sensitive resources, and natural processes

• Provide opportunities for varied levels of recreational use

• Provide quality interpretive and educational programs

• Direct visitors to locations able to withstand heavy use

• Manage major attraction areas to allow visitors to enjoy the resource with minimal environmental damage

• Manage for the protection and maintenance of cultural resources, including historical and archeological sites

The Open Space zone would be characterized by relatively undisturbed natural areas that receive only incidental or casual use. Maintenance of these conditions would allow for the protection and enhancement of the biological, hydrologic, scenic, cultural, and scientific ORVs while providing access to diverse visitor activities.

The visitor experience in this zone would be self-directed, with few visitor or management encounters, which would contribute to the diversity of experiences in the recreation ORV. The Open Space zone would be managed with very low tolerance for resource degradation from visitor use to protect and enhance biological, hydrologic, scenic, cultural, and scientific ORVs. Visitation levels may be controlled by parking limitations and by the lack of shuttle bus stops. These limits on use and facilities would allow natural areas to remain relatively unimpaired and to receive continued protection, restoration, and enhancement.

There would be limited trails and interpretive facilities. These would direct visitors away from hazardous areas and sensitive ORVs, such as unique wetlands, and promote understanding of natural processes. These areas would be generally quiet with limited facilities. The areas could be relatively easy to access or require considerable walking and skill to access. Though not directly accessible by vehicles or from parking areas, noise from nearby vehicles could affect visitor experiences in this zone.

Resource protection activities in this zone would include preservation of cultural resources and restoration of natural processes impacted by contemporary development, restoration of natural flood cycles and river channel dynamics to sustain native plant and wildlife species, and use of fire management practices called for in the Fire Management Plan to enhance biological and hydrologic ORVs. This zone also encourages the protection and enhancement of cultural resource ORVs, including archeological sites, by limiting development and access. Restoration of natural resources such as wetlands and meadows would also contribute to the restoration of the cultural landscape.

Activities – The following activities would be typical in this zone:

• Hiking and walking

• Photography and nature study

• Stock use in specified locations

• Swimming and wading

• Fishing

• Rock climbing

• Very limited interpretive programs (e.g., guided walks for small groups)

Facilities – The following facilities would be allowed in this zone:

• Vehicular roads could be realigned or relocated where they do not adversely affect ORVs

• Limited turnouts for short-term parking and scenic viewing or shuttle bus stops

• Limited unpaved trails for hiking

• Limited interpretive signs to protect natural or cultural resources or to promote understanding of natural processes

• Boardwalks, fencing, and other features to direct travel appropriately to avoid sensitive resources, such as meadows

• Bridges where necessary for access, improved circulation, safety, and resource protection

• Utilities (wells, utility lines, pump stations, and other facilities where they are screened from view)

• Minimal utility crossings of the river, only where necessary to support park operations

The following are examples of facilities that would not be allowed in this zone:

• New roads and paved trails

• Day-visitor parking

• Support facilities, such as restrooms and picnic tables

• Interpretive centers

• Food services

• Bicycle paths

• Non-motorized watercraft launch/removal facilities

• Campgrounds and lodging

The Undeveloped Open Space zone would be managed as "de facto" wilderness, primarily free from signs of human presence due to its inaccessibility. This zone would be used to protect those areas outside designated Wilderness that have limited or no trail access, such as the area west of the Wawona Campground along the South Fork. While Undeveloped Open Space areas would remain in pristine condition, visitors could experience some human influence due to noise from nearby roads. Typical activities would be hiking, rock climbing, swimming, nature study, and fishing. Access would require considerable effort because of lack of trails.

This zone would be managed in a similar manner as the Untrailed zone (1A) protecting and enhancing biological, geologic, hydrologic, cultural, scenic, and scientific ORVs through limitations on development and access. The following facilities normally allowed in the Open Space zone (2A) would not be allowed in this zone. Other prescriptions from the 2A zone would apply.

• Roads, either existing or new

• Turnouts

• Interpretive or directional signs

• Trails, boardwalks, or fencing

• Bridges

• Utilities

The Discovery zone would be characterized by relatively quiet natural areas where visitor encounters are low to moderate, which would contribute to the diversity of experiences in the recreation ORV. However, during high-use periods, some concentrated use and more frequent visitor encounters could occur on trails that link destination points through the Discovery zone. The Discovery zone would be managed with low tolerance for resource degradation from visitor use, emphasizing the protection and enhancement of biological, hydrologic, scenic, cultural, and scientific ORVs as well as emphasizing low-intensity types of use in recreation ORVs. Limits on use and facilities would allow natural areas to remain relatively unimpaired, when they are not close to one of the few access roads. There would likely be trail access and interpretive signs at principal features and gathering areas, but the visitor experience would be largely self-directed. Areas in the Discovery zone could be used by individuals or smaller organized groups. Access to these areas could require a moderate level of physical exertion, although some locations would be served by an access road and parking turnouts.

Within the Discovery zone, visitors would be likely to experience a variety of resources, including distant and close-range scenic views as well as opportunities to wade, swim, or fish in the river and to observe wildlife and plants. If use levels impacted resources, resource protection measures could be used, such as fencing and signs to direct travel from sensitive resources, well-marked trails and boardwalks, recycling and trash containers, relocation of shuttle bus stops in this or adjacent zones, or other measures as needed.

Resource protection activities in this zone would include restoration of natural processes impacted by past or current human use, restoration of natural flood cycles and river channel dynamics to sustain native plant and wildlife species, and use of fire management practices called for in the Fire Management Plan to enhance biological and hydrologic ORVs. This zone also encourages the protection and enhancement of cultural resource ORVs, including archeological sites, by limiting development and access. Restoration of natural resources such as wetlands and meadows would also contribute to the restoration of the cultural landscape.

Activities – The following activities would be typical in this zone:

• Hiking and walking

• Bicycling

• Photography and nature study

• Stock use in specified locations

• Swimming and wading

• Fishing

• Rock climbing

• Picnicking, relaxing, and gathering at informal locations

• Limited interpretive opportunities (e.g., informal ranger contacts, guided walks for small groups)

Facilities – The following facilities would be allowed in this zone:

• Vehicular roads and improved trails (could be realigned or relocated where they do not adversely affect ORVs)

• Small turnouts for trail access parking, scenic viewing, or shuttle stops

• Trails for hiking and through-trails for bicycling

• Minimal restroom facilities as needed to protect resources

• Fences, boardwalks, platforms, and other features to direct travel around sensitive resources

• Interpretive, directional, and safety signs

• Bridges where necessary for access, improved circulation, safety, and/or resource protection

• Utilities such as well sites, utility lines, pump stations, and other facilities (where screened from view)

• Minimal utility crossings of the river, only where necessary to support park operations

The following are examples of facilities that would not be allowed in this zone:

• Day-visitor parking

• Picnic facilities

• Non-motorized watercraft launch and removal facilities

• Interpretive centers

• Food services

• Campgrounds and lodging

The Day Use zone is intended to be applied to popular park destinations, where visitors could spend significant periods of time enjoying the park resources in a relatively accessible setting. The Day Use zone enhances opportunities for visitors to enjoy more intensive recreational activities near the Merced River and could support a range of active recreational opportunities such as swimming, picnicking, and rafting, which would contribute to the diversity of experiences in the recreation ORV. Visitors would expect moderate to high numbers of encounters with other park users and crowding on certain peak days. Large groups could use these areas. Day Use areas could be accessible by automobile, shuttle bus, and by bicycle, with interpretive trails or other marked trails leading to waterfalls, beaches, and scenic views. In order to accommodate heavier and more concentrated activity, facilities such as parking areas, restrooms, fencing of sensitive areas, picnic tables, and recycling and trash receptacles would be allowed.

Resource protection activities in this zone would be comparable to those described in zones 2A and 2B. However, due to the larger volume of visitors, the Day Use zone would be managed with moderate tolerance for resource degradation from visitor use in specified areas. To protect and enhance cultural, biological, and hydrologic ORVs, more extensive resource protection measures could be needed to direct visitor use away from sensitive resources. Examples could include boardwalks adjacent to meadows or fencing to prevent trampling and overuse. By encouraging higher visitor use in the Day Use zone, adjacent Open Space and Discovery zones would experience the desired lower visitor use for these areas. Some Day Use areas also protect historic resources, such as continued use of the Wawona Golf Course.

Activities – The following activities would be typical in this zone:

• Hiking and walking

• Photography and nature study

• Picnicking and social gathering

• Bicycling

• Stock use in specified locations

• Swimming and wading

• Rock climbing

• Fishing

• Use of non-motorized watercraft

• Full range of interpretive programs (e.g., ranger-led walks, talks)

Facilities – The following facilities would be allowed in this zone:

• Roads and improved trails (could be realigned or relocated where they do not adversely impact ORVs)

• Day-visitor parking

• Turnouts for parking or scenic lookouts

• Bicycle trails

• Shuttle bus stops

• Support facilities (e.g., restrooms, picnic tables, telephones)

• Marked, maintained, and paved trails, including bike paths and interpretive trails

• Fences, boardwalks, walls, signs, and other features to direct travel appropriately around sensitive resources

• Non-motorized watercraft launch and removal facilities

• Interpretive, directional, and safety signs and exhibits

• Utilities such as well sites, utility lines, pump stations and other facilities (where screened from view)

• Utility crossings of the river (where necessary to support park operations)

• Bridges where necessary for access, improved circulation, safety, and/or resource protection

The following are examples of facilities that would not be allowed in this zone:

• Interpretive centers

• Food services

• Campgrounds and lodging

The Attraction zone would be applied to main park features that attract large numbers of visitors, such as viewing areas for Bridalveil Fall. Due to the high number of visitors, this zone would be managed with moderate tolerance for resource degradation in specified areas, not to exceed established standards. The visitor experience in this zone would be highly structured, with well-marked and often paved trails or other trails to guide visitors, which would contribute to the diversity of experiences in the recreation ORV. Visitors could expect a high level of encounters with other visitors in these moderately to very busy areas. Attraction areas could be accessible by automobile, shuttle bus, bicycle, and/or trail.

To accommodate high visitor use, substantial facilities such as restrooms, parking lots, bus access and parking, and picnic tables could be provided at the entry point of the attraction area or another appropriate site. Facilities would be concentrated within the attraction area to minimize the extent of development and impacts. As a result, many areas within an Attraction zone would have a well-used trail, but minimal developed uses away from the entry "hub" or access point. Trails could be paved, fenced, and well signed to reduce potential resource impacts. Visitor use in sensitive areas would be formalized and concentrated to avoid resource damage.

By encouraging higher visitor use in the Attraction zone, adjacent Open Space and Discovery zones would experience the desired lower visitor use for these areas. This zone also would ensure that visitors have the opportunity to enjoy the park's most popular features, some of which are designated scenic, recreational, or cultural ORVs (e.g., views of granite domes, Wawona Covered Bridge).

Activities and Uses – The following uses would be typical in this zone:

• Hiking and walking

• Photography and nature study

• Sightseeing

• Stock use in specified locations

• Swimming and wading

• Fishing

• Rock climbing

• Bicycling (only in specified locations, to ensure visitor safety and resource protection)

• Full range of interpretive programs (e.g., ranger-led walks, talks)

Facilities – The following facilities would be allowed in this zone:

• Roads (could be realigned or relocated where they do not adversely impact ORVs)

• Day-visitor parking (to accommodate visitor access and administrative needs at high use areas)

• Bicycle trails

• Shuttle bus stops

• Support facilities such as restrooms, picnic tables, telephones, stables, and limited food services (where appropriate)

• Marked maintained and paved trails, including bike paths, and interpretive trails. (Trails could be hardened to direct visitors and minimize resource damage. Fences, boardwalks, walls, signage, and other features could be used to direct travel.)

• Interpretive centers

• Interpretive signs, exhibits, displays, and kiosks

• Utilities such as wells, utility lines, pump stations and other facilities (where screened from view)

• Bridges where necessary for access, improved circulation, safety, and/or resource protection

• Limited utility crossings of the river (where necessary to support park operations)

The following are examples of facilities that would not be allowed in this zone:

• Non-motorized watercraft launch and removal facilities

• Campgrounds and lodging