The CMAGR is a live-fire training range that is essential for developing and maintaining the readiness of Marine Corps and Navy aviators. The range is also vital for training select Marine Corps and Navy land combat forces; including Naval Special Warfare (NSW) forces.

The CMAGR consists of about 459,000 acres of Sonoran Desert terrain punctuated by angular mountains and broad plains in Imperial and Riverside counties, California. Roughly 50 percent of the CMAGR (228,465 acres) is comprised of withdrawn land that is administered by the Bureau of Land Management (BLM). Nearly all of the remaining CMAGR land (229,903 acres) is administered by the Department of the Navy (DoN). BLM and DoN land is distributed in a pattern that closely resembles a checkerboard where the management of every other section (640 acres or 1 square mile) is alternately the responsibility of either the BLM or DoN. About 162 acres of land administered by the Bureau of Reclamation is also located in the CMAGR. The withdrawn land is reserved for military use for 20 years by the California Military Lands Withdrawal and Overflight Act of 1994 (Withdrawal Act). The current CMAGR land withdrawal will expire in 2014, but the DoN has a continuing military need for the range and has initiated the processes required to request Congress to renew the land withdrawal.

In accordance with the Withdrawal Act of 1994, the DoN has prepared a Draft Legislative Environmental Impact Statement (LEIS) that addresses the purpose and need to continue the land withdrawal for the CMAGR. The Draft LEIS also assesses alternatives for realigning the range boundary, determining the duration for the continuing withdrawal, and assigning DoN and BLM jurisdictions and management responsibilities for land in the range. In addition to an alternative that would retain the current range boundary, the Draft LEIS also assesses alternatives that would release land north of the Bradshaw Trail and south of the Niland-Blythe Road that is no longer needed for military purposes and that would generally align the boundary with the Bradshaw Trail and/or a segment of the Union Pacific Railroad.

The Withdrawal Act of 1994 assigns management responsibility for the withdrawn land in the CMAGR to the BLM, but leaves responsibility for managing the DoN land to that Department. The DoN conducts its environmental stewardship responsibilities in accordance with the Sikes Act while the BLM conducts its responsibilities in accordance with Federal Land Policy and Management Act (FLPMA). As a result of these provisions, the checkerboard land jurisdiction pattern, and important differences in Sikes Act and FLPMA guidance, land management at the range is complicated. To some degree, land management at the range also is encumbered by overlaps, redundancies, and gaps between BLM and DoN responsibilities. The Draft LEIS provides three alternatives for assigning BLM and DoN management responsibilities. One of these alternatives would continue the existing split between BLM and DoN responsibilities, but the other two would each consolidate and simplify the land management situation at the CMAGR by assigning all management responsibility to the DoN and relieving the BLM of a continuing active roll for the withdrawn land. One of these two alternatives would transfer management responsibility for the withdrawn BLM land to the DoN for the duration of the land withdrawal. The DoN would manage the entire range in accordance with the Sikes Act. The second alternative would transfer jurisdiction for the BLM land to the DoN. The transfer of jurisdiction would not be limited to a predetermined duration of 20 or 25 years, but rather would remain in effect until such time that the need for the range may end and it is deactivated and closed. Consolidating jurisdiction for all of the DoN and BLM land in the CMAGR with the DoN would also have the effect of making the DoN responsible for managing all land within the range in accordance with the Sikes Act.