Landmark Highlights 2023

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McLean Game Refuge Natural Areas, Connecticut, one of 74 sites that marked the 50th anniversary of NNL designation in 2023.


🙤 This report shines a light on some of the activities, events, and stories from 2023 for a sampling of the 604 National Natural Landmark (NNL) sites across the country. Public and private land stewards continue with tireless efforts to protect, restore, educate, and share the wonders that are the nationally significant resources at these sites.

In all things of nature there is something of the marvelous. ~ Aristotle


🙤 In December 2023, Secretary of the Interior, Deb Haaland, designated Glenwood Caverns and Iron Mountain Hot Springs in western Colorado and John Boyd Thacher State Park in eastern New York as the newest National Natural Landmarks (NNL). The National Park Service (NPS) is pleased to welcome these new sites that join 602 other outstanding NNL sites situated on public and private lands across the country. View the Press Release announcing the new sites.

interior o a cave with lights and wooden structure
Glenwood Caverns, part of the newly designated Glenwood Caverns and Iron Mountain Hot Springs NNL.

Glenwood Caverns Adventure Park

Glenwood Caverns and Iron Mountain Hot Springs provide an excellent example of a unique combination of carbonic and sulfuric acid speleogenesis, karst processes that have been operational from the inception of Glenwood Caverns millions of years ago through to the present. Iron Mountain Hot Springs contain active populations of diverse extremophiles that live in the thermal, sulfidic spring water and Glenwood Caverns host unique ecosystems containing endemic troglobitic species, unique biothems, and fossilized extremophiles.
Panoramic view of green mountains
The Helderberg Escarpment within the newly designated John Boyd Thacher State Park NNL.
The Helderberg Escarpment at John Boyd Thacher State Park, a striking example of a cuesta, exposes the most complete and minimally disturbed record of middle Paleozoic stratigraphy in the Appalachian Plateaus region, and perhaps across North America. The uniquely accessible, fossil-rich deposits provide a master section spanning 63-million years, foundational in the early study and understanding of North American geology and of widespread ancient mountain building.

Learn more here New Landmarks Reveal Stories Millions of Years in the Making Below and Above Ground.


Interpretative panel sign
One of the interpretive panels found along the trail system at Miramar Mounds NNL.
🙤 Miramar Mounds NNL, located within the Marine Corps Air Station Miramar in southern California, features a well-developed and biologically diverse mima mound-vernal pool topography, including 1,200 of the best examples of the air station’s roughly 5,000 true vernal pools. While the NNL is relatively natural overall, disturbed areas have provided space for creation of more than 100,000 square feet of new vernal pools interspersed with mima mounds. Dozens of basins were constructed as part of a mitigation project associated with the 1998 realignment of Naval Air Station Miramar to Marine Corps Air Station Miramar. Additional small projects have restored disturbed vernal pools on the site. Twenty-five years later, these restoration efforts have shown great success, now supporting thriving populations of San Diego mesa mint, San Diego button celery, and San Diego fairy shrimp - all federally listed endangered species. Establishment of an extensive trail system with interpretive panels on the geology, biology, and techniques of vernal pool creation and enhancement, makes Miramar Mounds NNL a frequently utilized laboratory for students of vernal pool biology and conservation, as well as a prized local conservation area.
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Monarch butterfly grove within Nipomo Dunes and Point Sal Coastal Area NNL in central California.
🙤 Monarch butterfly habitat is being protected, restored, and monitored at Nipomo Dunes and Point Lobos State Natural Reserves along California’s central coast. The Pismo State Beach Monarch Butterfly Grove, which is part of the Nipomo Dunes and Point Sal Coastal Area NNL, is one of only five sites in the state of California that has monarch butterfly counts of over 10,000 individuals annually. From late October to February each year thousands of butterfly's flock to this site seeking shelter from the freezing northern winter, clustering on the limbs of tall eucalyptus and Monterey cypress trees, which provide essential habitat for migrating monarchs. Adjacent to the grove is a natural garden with native flowering plants that provide nectar to the adult butterflies.

At Point Lobos State Natural Reserve NNL, park biologists are collaborating with the Xerces Society for Invertebrate Conservation to improve and monitor western monarch butterflies and other pollinators. The population of western monarch butterflies has declined 95% since the 1980s, due to a variety of reasons, including habitat loss and degradation, pesticides, and climate change. The Xerces Society provides climate-smart native plants to project partners who are willing to provide the time, labor, and land to develop pollinator habitats for western monarchs. ( and
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The globally rare pitch pine-scrub oak barrens within Albany Pine Bush NNL.

M. Brickle, University of Richmond.



🙤 Inch by inch or acre by acre, the Albany Pine Bush Preserve Commission (APBPC) and its many members and partners work to protect and restore the globally rare pitch pine-scrub oak barrens of the Albany Pine Bush NNL. Both the APBPC and its partner, the Mohawk Hudson Land Conservancy acquired more than 23 acres in the Town of Colonie, New York to add to the preserve in early 2023. These acquisitions brought the total preserve acreage to over 3,400 and provided the first direct connection to a pine barren preserve in nearby Schenectady. Filling in pieces between protected areas is a core goal of the APBPC to improve continuity for wildlife movement, public recreation and buffering development. Learn more.

calm stream in foreground with marsh grasses and trees in background
Marsh area within the North and South Rivers NNL in Massachusetts.
🙤 The North and South Rivers Watershed Association (NSRWA) and its partners have embarked on the South Shore Salt Marsh Restoration Prioritization Project thanks to a grant awarded by Massachusetts' Office of Coastal Zone Management in the fall of 2023. Both field and GIS methods will be employed to assess the condition and adaptability to sea level rise of salt marshes along the state's south coast, including those within the river-mouth estuaries of the North and South Rivers NNL. Based on these measures, marshes will be prioritized to inform and guide future research and on-the-ground restoration efforts that will build a more resilient coastline. For more, please visit: Prioritizing South Shore Salt Marshes for Restoration - North and South Rivers Watershed Association (
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Sampling for dragonfly larvae at Battle Creek Cypress Swamp NNL in MD (left) and Ell Pond NNL in RI (right).

Kim Curren (left) and David Gregg (right)

Connected Conservation

🙤 For the seventh summer, NNLs participated in sampling for the long-term, landscape-scale Dragonfly Mercury Project. In 2023, five NNL sites (Bear Meadows Natural Area, PA, East Inlet Natural Area, NH, Fort Worth Nature Center and Refuge, TX, Ell Pond, RI and Battle Creek Cypress Swamp, MD) collected larvae from 12 different sampling locations, adding to the data collected at over 160 other sites across the country. All years of dragonfly mercury summary data are available at

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Social media post announcing the addition of Lilley Cornett Woods in KY to the Old Growth Forest Network


🙤 At least three more NNL sites joined the Old Growth Forest Network (OGFN) in 2023, Lilley Cornett Woods, KY, Fort Worth Nature Center and Refuge, TX and Itasca Natural Area, MN. Every new forest designated as part of this network helps advance OGFN’s mission of creating a national network of protected old-growth forests and provides additional recognition of the importance of the forest resources at these sites and their value to the nation.
Learn more:
Collage of postage stamps featuring waterfalls
Harrison Wright Falls, within The Glens Natural Area, is featured as a stamp in the Forever Waterfalls stamp sheet (top row, 3rd from the left)
🙤 Harrison Wright Falls in Ricketts Glen State Park is one of 12 waterfalls across the country honored by the United States Postal Service (USPS) as part of the Waterfalls Forever stamps released in June, 2023. Harrison Wright Falls, located on Kitchen Creek, “drops over a broad ledge, producing a single curtain-type plunging fall which has formed a rather large pool at the base of the cliff” according to the World Waterfall Database. Located in northeast Pennsylvania, Ricketts Glen State Park is known for its 22 named waterfalls, 21 of which occur within the portion of the park identified as The Glens Natural Area. Designated an NNL in 1968 in recognition of the relict eastern deciduous forest and stream erosion leading to spectacular waterfalls, including the Harrison Wright Falls. U.S. Postal Service Honors Pennsylvania's Harrison Wright Falls in Ricketts Glen State Park with Forever Stamp - Bucks County Beacon
Image of Colorado license plate with numbers, dinosaur, mountains, and sun
New Colorado license plate honoring Stegosaurus, the state's fossil.
🙤 In May 2023, Colorado Governor Jared Polis signed a bill approving the creation of a special license plate to commemorate the Stegosaurus as the Colorado state fossil. Stegosaurus were first discovered and excavated along the Dakota Hogback in Morrison, Colorado in 1877, an area now designated the Morrison-Golden Fossil Areas NNL. The first nearly complete stegosaurus skeleton was discovered in the Morrison Formation eight years later 100 miles south near Cañon City, an area now designated as the Garden Park Fossil Area NNL. Named by famous paleontologist O.C. Marsh of Yale University during the “Bone Wars”, this iconic, armored herbivore has a storied history in this state and is a rich contributor to the significance of both area’s NNL designations. Colorado License Plates Go Prehistoric (
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Fossils that are part of the collection at Rancho La Brea NNL in Los Angeles, CA
Early in FY2023, coinciding with the 60th anniversary of the International Union of Geological Sciences (IUGS), was the release of the first 100 IUGS Geological Heritage Sites global list. The list was authored by 485 experts from more than 40 countries “as a communication tool, to interpret geological features and landscapes for the general public, to support awareness raising activities and promote the values of the geological heritage of our planet as tools for the regeneration of rural communities around the globe through the development of geo-tourism.” Seven U.S. sites are on the list including well-known iconic places such as the Grand Canyon and Yellowstone Caldera, along with two designated NNL sites, Late Quaternary Asphalt Seeps and Paleontological Site of La Brea Tar Pits (Rancho La Brea NNL) and Dry Falls and the Channeled Scabland (Dry Falls portion of Grand Coulee NNL). Learn more and download a pdf of the list here

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Unveiling the new bronze plaque at the dedication ceremony for Lanphere and Ma-le'l Dunes, CA. Photo by Bureau of Land Management.


🙤 On May 18, 2023, the Lanphere and Ma-le’l Dunes NNL was officially dedicated. Located west of Arcata, California, Lanphere and Ma-le'l Dunes is on lands owned and managed by two Department of Interior sister agencies, the Bureau of Land Management and U.S. Fish and Wildlife Service. Taking place on the 61st anniversary of the NNL program, ceremony events included an opening blessing by the Wiyot Tribe, remarks by agency officials, a representative from Congressman Huffman's office, and the California Conservation Corps, and unveiling of the newly installed NNL plaque. The ceremony was followed by educational walks and talks through the site. Designated an NNL in January 2021 by the Secretary of the Interior, Lanphere and Ma-le’l Dunes, California's 37th NNL, is an exemplary illustration of coastal sand dune ecosystems and contains an outstanding variety of dune habitats and associated wetlands; the site is remarkably undisturbed and yet easily accessible. Dunes Landmark Dedication | Bureau of Land Management (
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Social media post announcing the 50th anniversary of 36 NNLs.

Quinquagenary Anniversaries

🙤 Seventy-four sites were designated as NNLs in 1973 and thus celebrated their quinquagenary anniversary in 2023. Thirty-six sites received the distinction by Secretary of the Interior Rogers C.B. Morton in late May and 38 additional sites were designated by Secretary of the Interior John C. Whitaker in early October of that year. Happy 50th! The full list of anniversary NNLS can be found here

The following highlights how some sites celebrated their anniversaries and shared their stories on social media.
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Lily Whitman (Parks Coordinator), Austin Shank (Parks Director) and Tracey Collins (Parks Assistant Director), with Grand Caverns NNL in VA, present 50th NNL anniversary certificate at the Cave and Karst Expo.


Events and Free Admission:

🙤 Grand Caverns NNL in Virginia celebrated by hosting an inaugural week-long celebration and "Cave and Karst Expo" in conjunction with National Cave Week. The peak of the expo was on Saturday June 10, with invited partners from various private and agencies attending the expo and providing a wide range of educational activities and outreach materials for the public. Staff from the NNL program attended the event and was honored to recognize Grand Caverns with its 50th Anniversary certificate.
Interpretive displays and signs inside a visitor center
Interpretive signage greeting visitors during the free week of admission to Wesselman Park Woods NNL.
🙤 Visitors to Wesselman Woods in southern Indiana were treated to a full week of free admission at the end of May into early June in honor of and to celebrate the 50th NNL anniversary of this natural area. Designated as the Wesselman Park Woods NNL, this site is located within the city limits of Evansville and is one of the finest remaining large tracts of pre-settlement lowland mixed forest in Indiana. Containing a number of exceptionally large trees, it is unusual in that sweet gum and tulip tree are the dominant species.
Cake decorated with NNL program anniversary logo
Dinosaur inspired cake enjoyed as part of the 50th anniversary celebration of Morrison Fossil Areas NNL.
🙤 The Friends of Dinosaur Ridge (FODR) took the opportunity to celebrate 50 years of the Morrison Fossil Area NNL throughout the entire year, starting with a press release in January. Events included a Fireside Chat presentation by a retired Bureau of Land Management Geographer sharing photogrammetry done at Dinosaur Ridge over the past 25 years, a 70’s themed “Rock Out for the Ridge” fundraising gala, and an on-site event in November that included bagpipe music, remarks by state legislators, staff from FODR, History Colorado, National Park Service, and the Morrison Natural History Museum and the most amazing cake! Located only 30 minutes west of Denver, Colorado, the Morrison Fossil Area was the first major site of the discovery of giant dinosaur fossil bones in North America in the late 1800's, revealing the first quarries ever to produce iconic Jurassic dinosaurs. This site was expanded in 2016 to include three nearby areas expanding the dinosaur story told through the resources at this site through the end of the age of dinosaurs (Cretaceous Period) and thus renamed the Morrison-Golden Fossil Areas NNL.
Vintage photo of two people standing next to large tree truck
Meltzer Woods in Indiana was designated a NNL on November 7, 1973. Pictured are Mrs. Jackson and Mr. Meltzer with one of the largest trees at the site, a Shumard's red oak. Photograph taken May 1973.

Guided Hikes:

🙤 The Central Indiana Land Trust celebrated the 50th anniversary the NNL designation of Meltzer Woods with a nature hike, sharing the multi-generational conservation story of this site. Significant for its juxtaposition of two contrasting forest types (beech-maple and lowland mixed forests) and exceptionally large individuals of several tree species, this Indiana landmark has been owned and managed by the Central Indiana Land Trust since 2014. Before its current managers this tract of old growth forest had been protected for more than 100 years by the Meltzer family, leaving it undisturbed even as the surrounding area was logged and developed.
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Enthusiastic hikers celebrated the 50th anniversary of the Portland Arch as a National Natural Landmark.


🙤 The Indiana Department of Nature Preserves partnered with the Old Growth Forest Network to sponsor their celebration hike through the outstanding natural landscape of the Portland Arch NNL. The hike went through the Nature Preserve following the trail and visited the arch where hikers posed for photos and learned about the history of protection at the site as well as its inclusion in the NNL program. In addition to the hike, educational program materials such as note cards and stickers were provided, encouraging participants to learn more about the diverse landscapes found across the country.
Graphic logo with text "50 years Cedarburg Bog National Natural Landmark"
Customized logo celebrating 50 years of NNL designation at Cedarburg Bog
🙤 The University of Wisconsin-Milwaukee Saukville Field Station held a guided hike to celebrate the 50th anniversary of the Cedarburg Bog NNL. One of the largest and most outstanding bogs in southeastern Wisconsin, Cedarburg Bog serves as a refugium for many northern species of plants and birds and provides habitat for a great variety of wildlife. This site is part of the Wisconsin Natural Area System, an Experimental Ecological Reserve, and a prized area for research.
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Social media posts shared by landowners celebrating 50th years of NNL designation at Oak Orchard Creek, NY, Orono Bog, ME and Cumberland Caverns, TN.

Social Media:

News and shout-outs of anniversaries were also shared far and wide through the various social media outlets.
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Bronze NNL plaque at Garden Park Fossil Area, CO.


Education and Outreach

🙤 In response to the excitement surrounding recent finds of a Jurassic tibia and fibula of a giant sauropod in southern Colorado, the Friends of the Royal Gorge Regional Museum and History Center and the Western Interior Paleontological Society hosted an all-day “Paleo To The People” Fossil Symposium in Cañon City, Colorado. No stranger to fossils, this area has been long known for revealing stories of the long-ago past and this public event provided a great opportunity for owners and managers of the area’s two NNLs, Garden Park Fossil Area and Indian Springs Trace Fossil Site, to share what’s known about the fossil resources, their significance, and why they are so important to study and protect. The recorded symposium can be found here
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Creelsboro Natural Bridge NNL plaque presentation to the Goff family. Pictured are NPS representatives with Thomas Henry Goff (holding the plaque), Mae Lorene Goff, and Diana Goff.
🙤 Creelsboro Natural Bridge NNL, located in Russell County, Kentucky, recently had a television debut! This site, referred locally as “The Rock House”, is one of the largest natural bridges in the eastern United States and represents an outstanding example of a geological process called stream piracy. In summer 2023, The Kentucky Network (Public Broadcasting Service) traveled to the NNL to film on location and capture the unique conservation history, geology, and natural beauty of this site for their “Kentucky Life” series. The documentary features the site’s private landowner, whose parents worked tirelessly in the 1980s to protect the Creelsboro Natural Bridge from plans to expand a nearby dam that would flood the area. Their conservation legacy is carried on to this day and Rock House continues to be a source of inspiration, peace, and revival. Watch the documentary at
Footpath through a forest of large trees
Giant grove of red cedar trees at Hobo Cedar Grove NNL.

Brian Jolley

🙤 Hobo Cedar Grove and Botanical Area NNL, a landmark found within the Saint Joe Ranger District of Idaho’s Panhandle National Forests, hosted local 6th grade students participating in a Resource Tour. Students toured the grove and learned about the significance of the red cedar trees, the species Latin name (Thuja plicata), how to determine the age of the trees by counting rings, and worked together to measure the trunk diameter by seeing how many students it took to wrap their arms around the base of a giant red cedar. The event was a great opportunity for the U.S Forest Service to collaborate and partner with the Idaho Department of Lands, University of Idaho Extension Office, and the timber industry to provide an enjoyable field experience for local students to learn and connect with nearby natural places.
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Attendees at the Garret Mountain Reservation Earth Day celebration.

Friends of Garret Mountain

🙤 Friends of Garret Mountain collaborated with Passaic County to hold an April 2023 Earth Day celebration at Garret Mountain Reservation in northeast New Jersey. Many environmental groups and organizations participated with informational tables, nature walks and activities for all ages, as well as a ceremonial tree planting. Traveling NNL banners were proudly on display and programmatic educational materials shared with the public. The Reservation is part of the Great Falls of Paterson-Garret Mountain NNL, which was designated for its excellent illustration of jointed basaltic lava flow.
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Participants at Floodfest 2023.

Washington State Parks

🙤 During the summer of 2023, hundreds of visitors joined tribes, federal and state agencies, and local environmental groups at Dry Falls Visitor Center in central Washington to participate in Floodfest 2023. The National Park Service brought its mobile visitor center and joined Washington State Parks staff to talk about the unique landscape and cultures connected with the Ice Age Floods. Sun Lakes-Dry Falls State Park is contained within the boundaries of the Grand Coulee NNL, designated in 1965 as an illustration of a series of geological events including outpourings of lava, advance and recession of glacial ice, retreat of waterfalls, and the cutting of the Columbia River channel. The Grand Coulee is one of eight NNLs connected with the cataclysmic events associated with the Ice Age Floods that occurred at the end of the last Ice Age (18,000-15,000 years ago), and completely transformed the landscape of the area.
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NNL sites detailed as part of the Ice Age Floods National Geological Trail within the NPS App.

Digital Media

🙤 In addition to in-person educational opportunities, the story of the Pacific Northwest’s ice age floods is getting broader digital presence, including within NPS’ official app. The Ice Age Floods National Geologic Trail was established by Congress in 2009 to tell the stories of the floods broad geologic events and invite people to discover and explore the resulting landscapes through public and private collaboration. The NPS’ role is to coordinate planning, development, and interpretation among the many public and private partners associated with the trail. The eight NNLs associated with the floods are now prominently called out when exploring the Ice Age Floods National Geological Trail park within the NPS App. Detailed descriptions of the resources and their relation to the ice age flood story are provided for each NNL site, allowing the public to explore this story in person via scenic view/photo spots or explore and learn virtually from anywhere.

Woman stands on geometric shaped rocks with blue sky and clouds in background
Columnar basalts at Drumheller Channels NNL.

Rebecca Latson

🙤 This landscape scale story has garnered additional light as part of a “Photography in the National Parks: Exploring the Ice Age Floods National Geologic Trail” series produced by National Parks Traveler digital magazine. Part 3 pays tribute to the formation of Drumheller Channels NNL and includes photographs of the landmark.
fossilized animal skeleton at excavation site
Adult female barrel bodied rhino skeleton at Ashfall Fossil Beds NNL in NE.
🙤 The NPS Paleontological Program has taken the lead, in partnership with the NNL Program, to feature a different NNL designated for paleontological resources in each edition of Park Paleontology News, starting in Fall 2023. Ashfall Fossil Beds in northeast Nebraska is the first featured landmark site in this series.
Take in many other articles related to fossil interpretation, protection, resource management, new discoveries, and the world of paleontology and paleontological resources management in current and back issues.
Line drawings of an ancient coral reef and gingko leaves
Newest NNL coloring pages.
🙤 Two new NNL Prehistoric Life Coloring Pages were added in 2023, bringing the collection to 15. Hand-drawn images are now available representing an ancient Devonian reef (such as that found as Ohio Coral Reef (Falls of the Ohio) NNL) and a prehistoric gingko tree (like that found at Gingko Petrified Forest NNL in WA). A collection of fossils as represented at units of the National Park System is also available.
Group of six people with desert cactus in background
NNL Program staff (L-R) Adrienne Lindholm, Carolyn Davis, Heather Eggleston, Laurie Lee Jenkins, Deb DiQuinzio, Leo Acosta.


🙤 Six NPS employees are committed to advancing the work of the NNL Program and supporting landmark owners. Contact information for program staff can be found here.

Part of a series of articles titled Landmark Highlights.

Last updated: May 16, 2024