Two of the Sonoran Desert's seven subdivisions extend into Arizona. The botanical diversity of the Goldwater Range is a blend of the Arizona Upland and the Lower Colorado Valley, with some elements of a third subdivision, the Central Gulf Coast. The Arizona Upland subdivision includes some of the most famous and picturesque portions of the Sonoran Desert. The greater amount of precipitation results in increased stature, density, and number of dominant and subdominant species. This subdivision occurs on the portion of the Goldwater Range east of State Route 85, where the landscape consists of mountains and bajadas.
Dominant vegetation includes palo verde, saguaro cactus, and ironwood.
Candidate species are those for which sufficient information on biological vulnerability and threats to support proposals to list them as endangered or threatened. This cactus has been documented to occur at five locations in Pima and Pinal counties, Arizona, and in Sonora, Mexico. As a wildlife resource, the Barry M. Goldwater Range is significant as the primary U.S. habitat of the endangered Sonoran pronghorn antelope, a significant habitat for desert bighorn sheep, and a relatively well-protected expanse of Sonoran Desert in which natural ecological processes are predominant. Diverse populations of native wildlife have generally benefited from the remote location of the range and the near exclusion, since the range was established, of potentially competitive land uses, such as livestock grazing, mining, and agriculture. Additionally, military use of the Goldwater Range has sharply limited public access, and, therefore, some of the environmental damage associated with public use, such as indiscriminate off-road driving.