Mixed foothill shrublands occupy drier slopes and openings within the forest community, where Gambel’s oak, mountain mahogany, skunkbrush and snowberry are the dominant species. Along drainages, chokecherry and American plum commonly grow with Gambel’s oak. Grasslands are an interesting association of short grass prairie, tall grass prairie, montane grassland and introduced species. Barren rock outcrops and cliffs support lichen and moss communities. A variety of riparian and wetland communities are present along Cherry Creek, tributary drainages, and on seeps and springs. Wetlands support healthy and diverse plant and animal communities by filtering contaminants and anchoring shorelines. Unique grotto (hanging garden wetlands) occupy ceilings and floors of dissolution caverns along the western canyon walls. They contain mosses, liverworts, ferns and vascular plant species representative of the last ice age.