Castle Rock is in the Colorado Foothills Life Zone. The hillsides are covered with meadows of grass, small plants, scattered juniper trees and open ponderosa pine woodlands. Other trees common in the area include Gambel oak (scrub oak or oak brush) and pinyon pine. Local wildlife includes the American badger, American black bear, bobcat, coyote, Colorado chipmunk, crow, garter snakes, gray fox, mountain cottontail rabbit, mountain lion, mule deer, pocket gopher, porcupine, skunk, and tadpoles. Birds found in the area include the golden eagle, peregrine falcon, sharp-shinned hawk, black-billed magpie, red-tailed hawk, pinyon jay, and western tanager.