Elk and Vegetation Management Plan

The Elk and Vegetation Management Plan was implemented in 2008 to address the negative impacts of excessive winter elk herbivory on riparian wetland plants that are key components of wetland ecosystems.

 

Bull elk in winter

NPS

 

The Rocky Mountain National Park (RMNP) Elk and Vegetation Management Plan (EVMP) was implemented in 2008 to address the negative impacts of excessive winter elk herbivory on riparian wetland plants that are key components of wetland ecosystems. Riparian wetlands provide important benefits to both wildlife and people including wildfire breaks, clean water, and critical habitat for many plants and animals.

Elk are a natural component of wetland ecosystems in RMNP. The impact of elk browse on vegetation in the park and the surrounding landscape was historically regulated through predation and harvest by Native peoples. Beginning in the 1800s, expanding settler activity followed by a series of management practices in the 1960s resulted in an unnaturally large, effectively non-migratory, elk population that peaked in the late 1990s-early 2000s. This led to heavy use of wetlands on the elk winter range near the town of Estes Park. As a result, much of the aspen and willow habitat, which is critical for many other plants and animals, was lost. The EVMP focuses on restoring winter elk populations and riparian vegetation communities to their natural levels to promote healthy, functioning, riparian wetland ecosystems.

 

 

Map of primary winter range, area of potential distribution change where elk are now wintering in greater numbers, and primary summer range in RMNP. The elk core winter range sits within the primary elk winter range and was the area with the highest concentration of elk when the EMVP was written.

NPS

Elk Ecology

Elk in RMNP are part of a regional, migratory population that uses areas inside and outside of the park during different seasons.

In summer, elk migrate to high-elevation ranges in the subalpine and alpine ecosystems of RMNP, as well as the Kawuneeche Valley. Elk diets during summer are primarily grasses and flowering plants. In September, elk migrate to their lower-elevation winter range that spans from the Estes Valley east to the Colorado plains. During this time, elk diets shift to consuming more woody shrubs like willow and aspen. Within the elk winter range, areas of highest winter elk use are considered the “core winter range” while areas of less intense elk use are referred to as the “noncore winter range.”

Throughout the 20th century, increasing elk populations resulted in higher and more concentrated browsing on plant communities, especially during winter.

 

History of Elk Management

From stories passed down through generations and archeological evidence, Native peoples have relied on elk for thousands of years in and around present-day RMNP. Conversations with Native knowledge experts of the Rocky Mountains remind park managers that human intervention has always been part of keeping the ecosystem healthy.

During the 1800s, expanding settler activity led to the local extirpation of elk through market hunting. Native predators like wolves and grizzly bears were also eliminated by settlers from this region, and keystone beaver populations were significantly reduced due to trapping. In 1913-1914, approximately 25 elk were reintroduced to the Estes Valley outside of what is now RMNP. Without natural predators and Native hunting practices, the elk population steadily grew to an estimated 1,000 animals by 1944.

From 1944 to 1968, park staff actively managed the elk population by regularly removing animals to maintain numbers between 350 and 800. In 1968, the National Park Service (NPS) adopted a new management philosophy of "natural regulation" - essentially allowing the ecosystems to self-manage without human intervention. This approach led to a dramatic population increase, with winter elk numbers peaking between 2,800 and 3,500 animals from 1997 to 2001. This is the highest recorded density for a free-ranging elk population that wasn’t artificially fed by people.

Research initiated in 1994 revealed significant ecological consequences of this population growth. Several aspects of the winter elk population were found to be outside the natural range of variation, including overall population size, migration behavior, and core winter range densities. This larger, less migratory, and more concentrated population continued to have negative impacts on sensitive wetland plant communities and beaver populations already impacted by human activity.

In 2008, RMNP implemented the EVMP to address the negative impacts of excessive winter elk herbivory on riparian wetland plants and the species that depend on them.

 

At its peak, the winter elk population in RMNP had the highest recorded density for a free-ranging elk population that wasn't artificially fed by people.

NPS Photo

The EVMP in Brief

The goal of the EVMP is to promote healthy, functioning riparian wetland ecosystems by restoring winter elk populations and riparian plant communities to more natural levels. The EVMP utilizes an adaptive management framework with several phases, including:

1. Collecting Baseline Data
2. Defining Management Goals or “Future Desired Conditions”
3. Implementing Management Tools
4. Monitoring Progress
5. Incorporating Results into Future Management

This iterative process allows park managers to make science-based management decisions, track the effectiveness of those decisions over time, and revise strategies based on new information to improve results. Each phase of the EVMP’s adaptive management framework is detailed below.

The full Elk and Vegetation Management Plan is available here.

 

1. Collecting Baseline Data

A variety of research studies were conducted before and during the planning process to provide the information needed to develop the EVMP. Research included an NPS and U.S. Geological Survey research initiative comprised of interdisciplinary studies that assessed the elk population and ecological effects of elk in the park.

A key part of this research initiative was developing an ecosystem model to evaluate habitat and species connections over different spatial and time scales. Colorado State University researchers used this model to predict how various park management scenarios would affect elk populations and winter range conditions.

 

Nearly 30 Year of Data Inform EVMP

Explore EVMP Baseline Research Here

 

2. Defining Management Goals

The EVMP outlines long term management goals, or “future desired conditions,” for winter elk populations, aspen communities, willow communities, and upland herbaceous plants on the elk winter range. Broadly, these management goals include:

1. Limit the number of elk overwintering in the park to a maximum of 800 elk.
2. Increase the proportion of regenerating aspen stands on the winter range to at least 45% and increase aspen recruitment (i.e., the number of small, young aspen stems growing into larger, older stems) on the elk winter range.
3. Increase willow cover to 70% in suitable habitat, increase willow height beyond the height of elk browsing, and reduce rates of willow browse on the elk winter range.
4. Decrease and diversify herbivory levels on upland herbaceous plants across the elk winter range.

Due to the long-term nature of vegetation response, the EVMP also outlines 20-year interim goals to measure progress toward the plan’s overall future desired conditions.

 

3. Implementing Management Tools

To achieve the future desired conditions above, the EVMP allows park staff to use a diverse set of management tools including elk culling, exclosure fences, and vegetation planting to promote restoration.

• Elk culling is a management tool that uses NPS personnel and authorized agents (including qualified volunteers) led by NPS personnel to remove elk from the park population by lethal means. The number of animals culled annually, if any, changes based on estimates from population surveys. A total of 131 elk were removed from the park population during the winters of 2009-2011. Culling has not been necessary since 2011 because winter elk population estimates have been at or below the maximum population target of 800 elk overwintering in the park.

• Exclosure fences are one of the primary conservation tools that protect critical habitat from elk browsing. These fences are temporary and will be removed when vegetation has recovered, and park staff determine that ungulates will not move in and consume the restored vegetation. Exclosure fences are only present on the elk core winter range and the Kawuneeche Valley and encompass just 6% of the area in the park winter range.

• Willow stem planting inside exclosures may expedite wetland recovery. In heavily impacted areas - such as those burned by wildfire, those lacking enough mature willow to produce seed, or those with limited area suitable for new willows to become established – active planting may be the best option to jumpstart plant growth.

Other tools, like elk fertility control and elk redistribution via hazing, were considered as part of the EVMP but ultimately dismissed due to feasibility, cost-effectiveness, and effectiveness.

 

Elk Culling

NPS/ B. Beach

Exclosure Fencing

NPS/ A. Schonlau

Willow Stem Planting

NPS

 

4. Monitoring Progress

Monitoring allows park managers to track the effectiveness of management actions and adapt strategies based on data collected.

Park staff and research partners monitor winter elk populations annually using data collected during ground surveys. During ground surveys, staff and volunteers document the number of elk, their sex, and age. Elk survey data, along with information on elk harvest and mortality outside the park boundary are fed into a model that produces an annual estimate of the number of elk overwintering inside the park.

Park staff also measure plant growth and regeneration. The EVMP uses a network of 256 vegetation monitoring plots in aspen, willow and upland shrub areas to monitor growth. Monitoring plots are in both fenced and unfenced areas of the core winter range and unfenced areas of the noncore winter range. Every five years, park staff visit all vegetation plots and use a rigorous monitoring protocol to collect data on the size and number of aspen stems, willow height, willow canopy cover, and signs of animal presence (elk, moose, deer, and beaver).

In addition, park staff annually visit a subset of willow plots to record browse impacts on willow shrubs. This allows them to calculate willow offtake, or the percentage of willow stems eaten by ungulates.

Baseline conditions recorded at the time of plot establishment are compared to more recent measurements to assess progress toward the desired vegetation conditions.

 

Field staff collect vegetation data to understand growth over time.

NPS

5. Incorporating Results into Future Management

In 2023, park staff conducted the 15-year re-sampling of the vegetation plots to evaluate the progress of the EVMP. The results of this sampling provide important information on management progress and challenges, and provide science-based direction for future management actions to accomplish the overarching goal of wetland restoration.

 

 

 

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  Kawuneeche Valley Restoration (KVRC)

  The Kawuneeche Valley Restoration Collaborative brings together agencies and organizations focused on restoration of the Kawuneeche Valley.