High Plateaus, Smelly Caverns, and Coastal Dunes, Meet the Nation’s Newest Natural Landmarks

Image of sunset and rocks, cave features, and coastal dunes
Left to Right: Sunrise at Bear Rocks Preserve and Allegheny Front Preserve, photo © Kent Mason/Sulfur deposit at Sulphur Cave and Spring by Norm Thompson/Coastal dunes at Lanphere and Ma-le’l Dunes by Andrea Pickart

The National Park Service is pleased to introduce you to the newest National Natural Landmark (NNL) sites:

  • Bear Rocks and Allegheny Front Preserve, WV
  • Sulphur Cave and Spring, CO
  • Lanphere and Ma-le'l Dunes, CA

Designated by Secretary of the Interior David H. Bernhardt in January 2021, these natural areas become sites 600, 601 and 602 in the National Registry of Natural Landmarks. And, we are excited to honor and welcome as partners, The Nature Conservancy, the City of Steamboat Springs Parks and Recreation, and the Bureau of Land Management and US Fish and Wildlife who are the stewards of these sites, respectively. NNL designation is given in recognition of the site’s significant natural features, and also heralds the landowner’s commitment for stewardship of these national treasures.

These new designations provide an awesome opportunity for everyone to celebrate the great diversity of the Nation’s natural heritage. So, let’s do just that by exploring these sites and see how they illustrate pieces of the geological and ecological story of America.

a man standing on the edge of a rocky cliff looking out onto a purple sky
High rock outcrop with views for miles with Bear Rocks Preserve

Photo © Kent Mason.

Located in Grant and Tucker Counties, Bear Rocks and Allegheny Front Preserve rocks the plateau world of the Allegheny Mountains in northeast West Virginia! Visiting Bear Rocks Preserve today, you’d see flat sedimentary rocks reaching right up to the edge of a high escarpment. Perched at 4,000-feet above sea level, feeling like you’re on top of world, you’d be treated to expansive views in all directions.

You would walk among red spruce trees, low-lying heath shrubs, rock outcrops and even bogs and marshes, at the lower elevations. It might even feel a bit Maine-ish, as many of the plant species here are typically found much farther north. The wind-swept, stunted appearance of the trees, and plants seemingly growing right out of the rocks, are a testament to adaptations that allow them to survive in such harsh conditions.

Even more mind-boggling is to realize that this high-elevation plateau is the result of continental plates that collided millions of years ago, uplifting the land into mountain landforms, and then slowly eroding away over the years by ice, rain, wind and water. A fascinating chapter in our natural story indeed!
2 piles of red thin worms in a cave.
Native sulfur and blood-red worms at Sulphur Cave and Spring

Photo by Norm Thompson.

Now, let’s travel nearly 1,700 miles, almost exactly due west. If your nose is detecting an odor, that means we are near our next outstanding site! Sulphur Cave and Spring is located just west of downtown Steamboat Springs, in Routt County Colorado. And talk about a harsh environment! The air in Sulphur Cave is filled with extreme amounts of hydrogen sulfide and carbon dioxide gases, making it a highly toxic environment; one in which most people might imagine couldn’t support living creatures. But on the contrary! Sulphur Cave has a rich ecological community thriving within its underground walls. The cave includes bacterial mats, biovermiculations (which are worm-like irregular patterns on the cave walls and ceilings that host an active microbial flora), gypsum crystals, native sulfur (thus the smell) and extremophiles, including snottites, and the blood-red worm (Limnodrilus sulphurensis), discovered recently and determined to be unique to this cave.
a finger points at a dripping white cave feature
Cave snottites at Sulphur Cave.

Photo by Norm Thompson.

And did we really say cave snot?? Well, almost. Snottites, are mucus-like soda straws that hang from the cave’s ceiling.

These uncommon cave formations contain bacteria that metabolize the hydrogen sulfide gas, excreting sulfuric acid in the process, which then dissolves the calcite-rich travertine that is host to the cave. Gas-metabolizing bacteria, crazy right?!
Yellow sand verbena along the beach at Lanphere and Ma-le'l Dunes, photo by Andrea Pickart
Yellow sand verbena along the beach at Lanphere and Ma-le'l Dunes, CA. Photo by Andrea Pickart.
And finally, we’ll travel yet another 1,200 miles due west until we hit the coast near Arcata, California. Located in Humboldt County on the north spit of Humboldt Bay is where you’ll find Lanphere and Ma-le’l Dunes. This scenic site boasts an outstanding variety of sand dunes ecosystems, from coastal dunes to beaches with American beachgrass and yellow sand verbena to open and stabilized dunes to dune forest islands. This site also contains a diverse array of wetland habitats including salt marshes, deflation plain swales, freshwater marshes and brackish wetlands.

And for all you geology fanatics, this site doesn’t disappoint there either! Lanphere and Ma-le’l Dunes contains exceptional examples of eolian landforms (aka things produced by wind), specifically those associated with sand dunes, such as beaches, foredunes, transverse dunes and stabilized dune forests.

Dune field at Lanphere and Ma-le'l Dunes, CA.
Dune field at Lanphere and Ma-le'l Dunes, CA. Photo by Andrea Pickart.
And if all that wasn’t enough, the site is remarkably undisturbed, and the aforementioned habitats contain virtually all the species of vascular plants typical of dune systems, including a number of rare species. Further, coastal dunes are among the most depleted ecosystems along the west coast, impacted by development and the introduction of European beachgrass, which was planted to stabilize these sands. European beachgrass dominates most dune locations, however, Lanphere and Ma-le’l Dunes may be unique in its almost total absence of this dominant weed.
fall foliage, coastal dune, and person in a cave
Left to right, Allegheny Front at Bear Rocks Preserve, Sulphur Cave and Spring, and Lanphere and Ma-le’l Dunes

Left Photo © Kent Mason, Middle Photo by Norm Thompson, Right Photo by Andrea Pickart

Now that you’ve glimpsed the amazing wonders of these three new NNLs, we will leave you with their significance statements that you can use to wow your friends, or casually drop into conversations and marvel at people’s reactions to your scientific aptitude….

Bear Rocks and Allegheny Front Preserve is the best example of a plateau within the Appalachian Plateaus Province, showcasing how tectonic activity and continental collision form regionally important mountain and plateau landscapes. The plateau at Bear Rocks Preserve exemplifies all three focus features: flat, sedimentary rock; high elevation with an obvious escarpment; and fluvial dissection. The high elevation and cool climate of Bear Rocks also supports a distinct and diverse ecological community dominated by cold-resistant plant species.

Sulphur Cave and Spring is a superb example of the process and products of bacterially-mediated sulfuric acid speleogenesis. Caves that are actively undergoing sulfuric acid speleogenesis are extremely rare and Sulphur Cave is the only known example in Colorado. The cave contains many uncommon cave features, including biovermiculations, gypsum crystals, native sulfur, snottites, and the recently discovered blood-red worm (Limnodrilus sulphurensis), which is unique to the cave, found nowhere else in the world.

Lanphere and Ma-le’l Dunes is the largest and best quality sand dune ecosystem representing coastal dunes from this area. The site is remarkably undisturbed and yet easily accessible containing an outstanding variety of dune habitats and associated wetlands. These habitats contain virtually all the species of vascular plants typical of dune systems, plus a number of rare species. The site is very scenic and affords visitors an inspiring view of a natural coastal ecosystem.

Last updated: January 21, 2021