One of the interesting features of trails like Emerald Pools, Weeping Rock, and Riverside Walk are the canyon walls. These vertical surfaces alternate between healthy plant commuties and bare earth. Errosion is a natural part of the Canyon's life. Rain, snow, and melting ice move layers of earth off the steep canyon surfaces while plants hold the earth in place. Here is an example - large tuffs of grass growing out of crevices are surrounded by bare rock.