In his five years at Arizona's Sonoran Desert National Monument, former manager Rich Hanson picked up a lot of trash. In just one cleanup, he and his staff gathered 12,000 pounds of bullet-riddled oil drums, fast-food garbage and computer monitors. "Slob shooters," as Hanson, who retired last spring, calls them, have also harmed the very resources he was sworn to protect – amputating saguaro limbs, shattering rock faces and splintering the trunks of palo verde, mesquite and other desert trees. Visitors to monument wilderness areas or the popular Anza National Historic Trail often pass unsightly roadside dumps.

It's a far cry from the "magnificent … untrammeled Sonoran desert landscape" President Clinton had in mind in 2001 when he designated a 487,000-acre national monument in the mountains, wide valleys and saguaro cactus forests southwest of Phoenix. Legal concerns made it impossible to set aside specific shooting areas, so, after much study, Hanson and his staff announced their intent to close the whole monument to shooting in a draft resource management plan released in August 2011.

But eight months later, after a one-day visit from Washington, D.C.-based hunting and shooting advocates, the upper echelons of the Bureau of Land Management abruptly reversed that decision, according to documents High Country News obtained through the Freedom of Information Act.

"This is not just turning a blind eye to someone else's science," says Wilderness Society attorney Phil Hanceford, who sued the BLM over the decision in September. "It's looking straight at their own science and completely disregarding their own recommendation."

Ray Suazo, director of BLM's Arizona office, explains that he didn't want to push the impacts of shooting elsewhere. "I'd love to be the place where we develop a model that works, where recreational shooters understand appropriate recreational shooting and it allows for other uses of the public land as well."

Land-management decisions are never free of politics, but what happened in Sonoran Desert National Monument appears to be an extreme example of the influence national-level special interest groups of all kinds can have on outcomes. Even Hanson was taken aback by the way local BLM staff recommendations were ignored. The decision, he believes, should have been made "more in the sunshine," rather than "outside the public comment process.

Suburban development lies behind much of the tension. With more people looking for places to fire guns, houses invading the desert, and dog walkers and joggers populating places shooters once had to themselves, Arizona land managers worry about safety and social conflicts, plus increased trash and vandalism. Drought has also increased the risk of shooting-caused wildfires. As a result, more managers are resorting to closures.

In 2001, the Forest Service closed 81,000 acres of the Tonto National Forest outside Phoenix to target shooting. Four years later, 71,000-acre Agua Fria National Monument, 40 miles north of Phoenix, proposed its own ban after archaeological sites were damaged. In 2007, the 129,000-acre Ironwood Forest National Monument, 30 miles from Tucson, did the same after shooters toppled giant saguaros with bullets. (Those closures took effect in 2010 and 2013, respectively.) By the time Sonoran Desert floated its ban in 2011, the BLM was drafting national policy to identify low-risk shooting spots and close high-risk ones.