The western flanks of Chigmit Mountains descent through arctic tundra-covered foothills in Lake Clark National Park and Preserve. This area provides many recreational opportunities to visitors and grazing areas to wildlife utilizing the unit. Caribou Moss or Reindeer Lichen "Cladonia rangifernia" is a common plant that makes up artic tundra. Lichens are unusual plants in that they are composed of both algae and fungi cells. Caribou moss is a light-colored, fruticose lichen that grows in well-drained, open environments.
As the common names suggest, caribou moss and reindeer lichen are important food of that species. The Inland Dena'ina used reindeer lichen for food by smashing the dry plant and then boiling it or soaking it in hot water until it is soft. They eat it plain, or preferably, mixed with berries, fish eggs, or grease. The Inland Dena'ina also boil caribou moss and drink the juice as a medicine for diarrhea. Due to acids in the plants, lichens may cause upset stomach especially if not well cooked.