Sonoran Desert desert is a popular route to attempt unauthorized entry across the border. The harsh conditions mean that the 3-5-day march, usually moving at night to minimize exposure to the heat, often ends in death. There are many National Parks and Monuments; federal and state nature reserves and wildlife refuges; state, county, and city parks; and government or nonprofit group operated natural history museums, science research institutes, and botanical gardens and desert landscape gardens. Sonoran Desert The Sonoran Desert is a North American desert which covers large parts of the Southwestern United States in Arizona and California and of Northwestern Mexico
Desert bighorn sheep the population is 18,965-19,040. The results of the state-by-state survey are shown to the right. In southern California, by 1998, only 280 individuals of the peninsular bighorn sheep population remained, and that population was added to the list of the United States' most imperiled species. Populations in three southern counties had suffered greatly from disease, development, and predation. As of 2008, about 800 peninsular bighorns are believed to populate the desert backcountry from the US-Mexico border to the San Jacinto Mountains, with known populations in Anza-Borrego Desert State Park. These gains, combined with Bush Administration policies, prompted the US Fish