The Surprising Role of Lichen: How RMNP was Made

Colorful Lichen on a Rock

Perhaps one of the most under-appreciated lifeforms in Rocky Mountain National Park are the large variety of lichens growing on the rocks and trees.  Not only are lichen colorful and an important food source for the park's beloved elk, but they actually played an important role in creating RMNP as we know it. 

Lichen are an amazing combination of fungus and algae that take in nutrients from the air, as well as through photosynthesis.  But it is the role lichens played approximately 16,000 years ago that we owe a little respect.  At that time, the glaciers receded from the lower parts of the park.  Lichens were some of the original colonizers on the newly exposed rocks.  Over time, lichens' small threads (called hyphe) that attach them to their rocks grow into the smallest cracks in the rock.  Gradually these cracks get larger and allow water to freeze and thaw thousands of times.  This process is what eventually breaks the largest rocks into tiny pebbles.  Breaking down rocks this way is what allows plants and tress to move into an area that was previously barren rock.

Even though lichens play a vital role in the ecosystem by creating soil and providing a hospitable environment for plants, and essential nutrients to many of the park's fauna, most people won't give them a second glance.  Maybe next time you are out exploring Rocky Mountain National Park, you'll take a moment to appreciate the beauty and power of the humble lichen. 

Blog post and photo provided by Jared Gricoskie of Yellow Wood GuidingFind out how you can book your own guided tour of RMNP by visiting