Steamboat’s Sulphur Cave designated as National Natural Landmark |

Steamboat’s Sulphur Cave designated as National Natural Landmark

Alison Berg, Steamboat Pilot
Steamboat’s Sulphur Cave has been designated by the National Parks Service as a National Natural Landmark.

STEAMBOAT SPRINGS — Those skiing at Howelsen Hill Ski Area likely won’t notice, but they are now skiing over a National Natural Landmark, which comes after the National Parks Service designated the Steamboat Sulphur Cave as Colorado’s latest landmark.

“It’s an honor to join a distinguished list of natural landmarks across our county and the 15 within Colorado that recognize the value these locations provide science and education,” said Angela Cosby, Steamboat Springs Parks and Recreation director.

Dave Steinmann, a biologist at the Denver Museum of Nature and Science, has been conducting research in the cave for decades and found a rare worm species there called limnodrilus sulphurensis in 2004, which he believes has evolved inside the cave for more than 10,000 years.

“The first time we saw the clusters of worms, I thought, ‘wow, I’ve never seen anything like this before,’” he said. “They’re very unique to Steamboat Springs.”

In addition to the worms, the cave’s ceiling is home to snottites. While they look similar to stalactites, snottites are the consistency of mucus and formed by bacteria that metabolizes hydrogen sulfide. Snottites are found only in a handful of caves worldwide, with others located in Italy and Mexico.

Brad Setter, Howelsen Hill and rodeo manager, said the cave contains elements that are harmful, so the city only allows scientific research groups with specific protective measures to enter the cave.

“The atmosphere down there is not conducive to most life on this planet,” Setter said. “It’s not a place you can go to without taking necessary precaution.”

Dave Steinmann, biologist at the Denver Museum of Nature and Science, studies the Steamboat Sulphur Cave.

Breathing in the mix of hydrogen sulfide, carbon dioxide and carbon monoxide in the cave can kill a person. Even one or two breaths could knock a person out, Fred Luiszer, a University of Colorado scientist who specializes in caves, told Steamboat Pilot & Today in 2008.

Since the cave has never been accessible to the public, Cosby said most people won’t notice a difference, but the federal title gives the city extra obligation to protect the cave due to the rare species and geological features inside.

“Sites are designated as NNL (National Natural Landmarks) because they contain the best remaining examples of specific biological and/or geological features,” Cosby said. “The natural features represented include aquatic and terrestrial ecosystems, geological processes and resultant land forms, and records of geologic history.”

While the cave is unsafe for most community members to explore, Cosby said those interested in seeing it can view the outside from behind the fencing barrier just west of lower Mile Run on Howelsen Hill.

“Each site is a piece of the larger picture that is the illustration of the great diversity of our nation’s natural landscape,” Cosby said.

Steinmann said Steamboat is known for its outdoor recreation and explorable features, but it’s important to also remember the area’s wildlife and natural species.

“This is a pretty special place, and although the public can’t really enter the cave, it’s a fun hike to it,” he said. “It’s also a really neat place to look into and know how Steamboat has some of the most unique and unusual species on our planet.”

The cave is Colorado’s 15th National Natural Landmark and Routt County’s first, joining the list which includes sites in Arapahoe, Clear Creek, Douglas, El Paso, Elbert, Fremont, Garfield, Hinsdale, Huerfano, Jefferson, Larimer, Las Animas, Park and Saguache counties.

Cosby and Setter both said they hope this designation helps inspire Routt County students to study science and biology, as they are living in the midst of rare wildlife species.

“It’s one thing to learn about biological and geological features, but to have a living example in your backyard will hopefully spur students to study science fields to a greater degree,” Cosby said.

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