Trespassing on Yuma Proving Ground is dangerous, illegal

By Mark SchauerDecember 6, 2023

A trail that crosses into a restricted area on Yuma Proving Ground’s Cibola range is so defined due to recreators dismissing the 'U.S. Government Property: No Trespassing' Sign.
A trail that crosses into a restricted area on Yuma Proving Ground’s Cibola range is so defined due to recreators dismissing the 'U.S. Government Property: No Trespassing' Sign. (Photo Credit: US Army photo) VIEW ORIGINAL

Trespassing on the vast desert ranges of U.S. Army Yuma Proving Ground (YPG)’s Yuma Test Center (YTC) is dangerous.

Unauthorized entry into any military installation is a crime, but the proving ground has a host of hazards that are as unique as its mission testing virtually every piece of equipment in the ground combat arsenal in a natural environment.

In addition to the possibility of unexploded ordnance from the proving ground’s distant history as a World War II training facility, YTC’s 1,300 square mile ranges accommodate the surface danger zones for test fires of powerful long-range artillery shells and airdrops of cargo parachutes carrying multi-ton pallets of equipment or military vehicles. The testing of laser targeting technology in the area also carries the risk of causing serious eye injuries to unwitting persons traipsing in areas that they do not belong.

The dangers to life and limb are bad enough, but trespassing within YPG’s borders can also degrade the proving ground’s range conservation efforts and mission readiness.

“We want to preserve wildlife habitat, but the larger objective is supporting our test mission,” said Daniel Steward, YPG wildlife biologist. “These ranges are our natural laboratory and we try to keep them as pristine as possible.”

Steward says that federal law allows for some public access to military installations, an obligation the proving ground takes seriously.

“We provide for some limited public access where it’s not interfering with our mission,” he said. “We permit hunting in very specific areas and with our range controllers notified of where it is taking place to keep people safe. If we have unauthorized access and range control is not aware of it, it puts people in danger and affects our test mission.”

Steward believes that some members of the public may conflate YPG with the Barry M. Goldwater Range (BMGR), a training range jointly controlled by the Marine Corps and Air Force southeast of YTC that allows significant public access to people who apply for and obtain a permit, particularly for off highway vehicle (OHV) use. Such a liberal policy is not possible at YPG, however.

“Our mission is so much different than that of BMGR,” explained Steward. “They’re not doing as intensive work on the ground as we do at YPG. Also, the experimental nature of YPG’s mission has a lot more safety and security concerns than theirs.”

Steward doesn’t anticipate any significant changes to this policy, either.

“The areas we do allow hunting in are very remote and with a volume of visitors we can sustain without impacting our test mission,” he said. “There is a huge demand for OHV recreation, and we just couldn’t sustain allowing unlimited public access.”

YPG’s successful wildlife conservation efforts have sustained a variety of creatures that are imperiled in many other places of the American West, from bighorn sheep and Sonoran pronghorn to fringe-toed lizards and the Sonoran desert tortoise. They have also provided ample habitat for numerous species of bats in several abandoned mines that predate the proving ground’s existence. The mines, however, also attract trespassers, which can wreak havoc on fragile roosting locations for the bats, natural predators of all manner of pesky insects.

“When there is a bat breeding colony in a mine, one entry is all it takes to wipe out an entire reproduction season for those bats,” said Steward. “A lot of bat species are very high conservation concern because of the lack of habitat availability.”

Additionally, Steward adds, isolated abandoned mines are extremely dangerous places for people to visit.

“Mines are flat-out hazardous,” Steward said. “They have bad air, unstable ground and ceilings, and deep, sometimes flooded shafts. They are real death traps. Stay out and stay alive.”