Years ago the U.S. Marine Corps (USMC) traded its horses for trucks and all-terrain vehicles. But now in California a herd of 18 Bureau of Land Management (BLM) mustangs are helping train Marines to travel places that motorized vehicles just won't go.

Alan Shepard, state leader for the BLM's Nevada Wild Horse Program, said the agency has a relationship with the USMC that dates back to the 1990s. The USMC receives some of its horses through BLM programs.

"In fact, almost all of the horses in the USMC color guard are BLM mustangs," he said

One such program involves the Northern Nevada Correctional Center. Under the center's long-term agreement with the BLM, inmates train wild horses brought to the correctional center's short-term holding facility, Shepard said