On March 2, 1999, the Board of Supervisors of Pima County, Arizona adopted the Sonoran Desert Conservation Plan. This Plan is the largest and most comprehensive regional multi-species conservation plan in the United States. These memorandums of understanding record the agreements made with cooperating agencies.

To prevent unwanted urban sprawl and unregulated development, it is most important that Pima County encourage and retain viable ranches. Ranching is a significant land use that has served to protect our natural open space, and it continues to be an important traditional industry that has shaped the rural landscape.