Santa Rita Experimental Range (SRER) is located 40 miles south of Tucson. Established in 1902, it is the oldest experimental range in the country. SRER includes more than 80 square miles, spanning Sonoran Desert at less than 3,000 feeet elevation and receiving less than 10 inches of precipitation, to semi-arid grassland scrub at 4,500 feet elevation and receiving about 18 inches of annual precipitation. Contiguous to SRER is a Wilderness Area in the Santa Rita National Forest, presenting a total gradient of protected land from less than 3,000 to over 9,000 feet elevation.

SRER was founded to study range recovery from drought and overgrazing, as well as sustainable grazing practices. Livestock grazing has been studied by university and government scientists at SRER for over 80 years. Parts of the rangeland have been excluded from grazing since 1903 and many ecological and wildlife studies have been conducted on grazed and ungrazed areas at SRER. A unique scientific resource is the archive of repeat photos, some as old as 1902.

SRER is available for research and education, and the Florida Canyon HQ includes both administrative buildings and lodging available for students and researchers. Resident staff members are all volunteers. Grazing fees and cabin rentals to the range's clientele provide operational funds.