Short-grass and mixed-grass prairie cover the gently rolling plain of the park, located at 5,500 feet of elevation. Soil type and historic land use determine local species composition. Dominant species of the mixed-prairie community include western wheatgrass, blue grass, purple threeawn, mat, muhly, needle-and-thread grass and false buffalograss.
There are sizeable wetland and cottonwood riparian habitats for the Front Range. Diverse wetland, riparian and aquatic plant communities established and now thrive as the water table rose along Cherry Creek, tributary drainages, around the reservoir and below the dam.