SARATOGA SPRINGS, Utah >> As a lover of ancient rock art, Steve Acerson usually roams Utah’s backcountry searching for images of hunters and rams carved on boulders and canyon walls. But one morning, on a hillside speckled with those prehistoric petroglyphs, he was also finding signs of a younger civilization: Shotgun shells. Bullets. Shredded juniper trees. Exploded cans of spray paint.

“It’s all been shot,” he said. “It’s just destroying everything.”

America’s cultural divide over guns has gone into the woods. As growing numbers of hikers and backpackers flood national forests and backcountry trails searching for solitude, they are increasingly clashing with recreational target shooters, out for the weekend to plug rounds into trees, targets and mountainsides.

Hiking groups and conservationists say policies that broadly allow shooting and a scarcity of enforcement officers have turned many national forests and millions of Western acres run by the Bureau of Land Management into free-fire zones. People complain about finding shot-up couches and cars deep in forests, or of being pinned down by gunfire where a hiking or biking trail crosses a makeshift target range.

Over the Fourth of July weekend in Pike National Forest in Colorado, a 60-year-old camper preparing to make s’mores with his grandchildren was killed when a stray bullet arced into his campsite. The camper, Glenn Martin, said “ow,” his daughter said, and when his family ran to help him, there was a hole in his shirt and blood pouring from his mouth.

“A war zone,” said Paul Magnuson, who owns a cycle shop in Woodland Park, Colorado, and rides mountain bikes in the same forest where Martin died. His customers have complained about bullets whistling overhead, and Magnuson said he had gotten used to yelling out to alert target shooters that he was coming.

“Every time in the woods, you feared for your life,” he said. “It was absolutely, completely out of hand.”

It is a fight playing out from the pine forests of North Carolina to the Pacific Northwest to the Lake Mountains here in central Utah, where hillsides with thousands of images of prehistoric rock art have become a popular shooting spot. Officials in the Croatan National Forest in North Carolina issued an emergency halt to target shooting after receiving hundreds of complaints. In New Mexico, homeowners upset by the crackle of gunfire are fighting a proposal to renew the permit for a gun range that has long operated on national forest land.

The federal agencies that manage national forests and open lands have tallied a growing number of shooting violations in the backcountry in recent years. The Forest Service recorded 1,712 shooting incidents across the country last year, up about 10 percent from a decade ago. More than a thousand of those reports ended with a warning or citation, but in some, Forest Service officers did not find who had fired or evidence of a violation after investigating a complaint.

The violation logs from the bureau are a tally of risky behavior: Shooting from vehicle. Weapon discharge in campground. Shooting at television. Using exploding targets. Shooting in “no shooting area.”

Gun groups say that they have been shooting safely on public lands for decades, and that accidents are rare. They say they have the same rights to use America’s collective backyards as four-wheelers, mountain bikers or backpackers.

When federal agencies have proposed closing areas to shooting, the National Rifle Association and other shooting groups have objected, urging members to write letters and attend meetings to keep the land open to guns. The NRA has also supported a bill backed by several congressional Republicans that would tell federal land managers to make sure public lands are open to hunters and people who shoot recreationally.

“Just the same as there should be areas on public lands for people to go mountain biking or mountain climbing, there should be areas for shooters,” said Lars Dalseide, an NRA spokesman.

But in Colorado, Sean Mooty, 26, said he had taken to draping a bright orange windbreaker over his backpack when he sets out in the Arapaho National Forest, which reported 103 shooting violations last year. He put a whistle on his pack, and when he hears gunshots, he said, he starts to blow it so people will know he is coming.

“All you can do is hear it,” he said. “Like a mixture of thunder and gunfire, just rolling through the mountains.”

Karie Rubertus, 46, an office manager, said she was jolted awake by gunfire while camping a few years ago at Rainbow Falls in Colorado, near the spot where Martin was killed. When she went to explore, she said, she spoke to a group of motorcyclists who had been firing guns most of the night and asked them to take a break. She said they had walked with her, unasked, back to her camper. She woke her husband and they left immediately.

“One of the most scary experiences ever,” she said.

Here in the Lake Mountains of Utah, Bureau of Land Management officials want to permanently ban shooting because they say it is jeopardizing hundreds of petroglyphs that Native Americans pecked onto sandstone outcroppings and boulders as long as 10,000 years ago. Advocates say the mountainside is an open-air museum, one where bullets have struck the petroglyphs, chipping and cracking the runic swirls and wiry images of people and animals.

“We’ve had serious damage,” said Kevin Oliver, district manager for the bureau’s West Desert district. “The shooting was so dense we had to do something.”

There have also been about 130 wildfires here over the past decade, some caused by bullet ricochets or exploding targets igniting dry cheatgrass. One bullet flew across the range and hit a bedpost in a nearby home, and land officials said high school students on a bus had to take cover to avoid careless gunfire. Cleanup crews have hauled away 20 tons of trash a year — refrigerators and car parts, clay pigeons and sofas, even bowling pins.

“Anything you don’t want in your garage, you take out there and shoot,” said Acerson, a retired state transportation worker.

Bill Pedersen, a director at the Utah Shooting Sports Council, acknowledged that some people dumped what he called “trigger trash,” but he added that thousands of responsible gun owners had been hunting and shooting in the area for decades. He shot pheasants and doves there as a teenager. In the years since, as Utah’s population has surged, new subdivisions have popped up on the private lands adjoining these federal parcels, putting more pressure on the land.

The Bureau of Land Management has proposed creating a shooting range, but gun advocates say it would be too small to accommodate them safely. They said previous shooting restrictions had already limited their activity, and they were angry at the prospect of another closing.

“Shooters are getting frustrated and upset,” Pedersen said. “What gives the BLM the right to go down and shut it down on a whim?”

Officials have limited shooting access for years in the Pike National Forest, including the site where Martin was killed; it was the first fatal shooting officials could remember.

Since Martin’s death, the Douglas County Sheriff’s Office has asked people who were in the area that day to allow their weapons to be tested, to see if they unknowingly fired the fatal shot. So far, investigators have tested five rifles, with none of them found to be the weapon in question. Martin’s daughter Carlie said they had complained about hearing gunshots when they arrived at the campsite, but they said forest officials had reassured them the guns were being fired in the other direction.

“You keep on asking why,” she said.

“One hundred ninety million acres of forest, and it has to hit Daddy?”

© 2015 The New York Times Company