Grand Canyon National Park scrublands are more precisely called desert scrub communities. A Mohavean desert scrub community extends from the Grand Wash Cliffs in extreme western Grand Canyon to near the Colorado River's confluence with the Little Colorado River. It is typified by warm desert species such as creosote bush and white bursage. Frost-sensitive species more characteristic of the Sonoran Desert such as brittle brush, catclaw acacia, and ocotillo can also be found along this stretch of the river. Species such as mariola, western honey mesquite, and four-wing saltbush, considered typical of Chihuahuan Desert species, also grow here. Upstream of the Little Colorado River, in Marble Canyon and on the Tonto Platform, species more characteristic of the Great Basin Desert predominate, such as big sagebrush, blackbrush, and rubber rabbitbrush.