On the morning of April 1, 2006, Harold Dennison went for a ride on his all-terrain vehicle in the woods surrounding his house on Stag Hill Road, in Mahwah, New Jersey. Mahwah occupies the northwest corner of Bergen County, where the Ramapo Mountains, stony foothills of the Appalachian range, loom over the intersection of routes 287, 17, and 87. It was one of the last towns in the region to succumb to suburban sprawl, and, although the old valley farms along the Ramapo River have mostly been replaced by million-dollar estates and cul-de-sacs with names like Stabled Way and Polo Lane, Stag Hill, about twenty-five miles from midtown Manhattan, remains a kind of world apart. Roosters far outnumber spaniels, and spare tires and rusting appliances vie for scenic predominance. Area teen-agers, recalling decades-old legends of unsuspecting people who climbed Stag Hill and never returned, dare one another to drive up at night. Dennison’s and his cousins’ families—the Manns, the Van Dunks, the De Groats, the De Freeses—have lived and hunted there for generations.

Most of the Ramapo Mountain woodlands, extending from Pompton Lakes, south of Mahwah, up to West Point, on the Hudson River, are now preserved as parks, where A.T.V.s are prohibited. But Stag Hill has traditionally been left alone, and blazed hiking trails steer clear of the residences by at least a mile in any direction. Dennison brought a switchblade with him, as well as a .22-calibre handgun, which he kept in a holster on his right side. He planned to take some target practice at one of the abandoned cars nearby, or, if he got lucky, to bag a deer or a wild turkey or some smaller game. “Basically, he was doing what every American kid does: go out in the woods and shoot off a couple of rounds,” his lawyer later argued. “It’s as American as apple pie.” Not in New Jersey. Dennison, a married man in his late fifties, soon ran into three park rangers, two men and a woman, who had wandered out of their jurisdiction during an “area familiarization” patrol, conducted on A.T.V.s of their own. They stopped him, and discovered that the handgun, for which he had no license, was loaded with hollow-point bullets, sometimes known as “cop killers.”

Word of the arrest spread quickly. Deep in the woods, near the ruins of an old goat farm, some of Dennison’s neighbors and relatives were gathering for a birthday cookout. Ancestors of the present-day Mann family once worked the farm. Now everyone referred to the spot as the German house, and scattered shotgun shells and broken beer bottles marked it as a common meeting place, for grilling venison or mackerel or bluegill. By late afternoon, when the rangers returned to the woods after booking Dennison at the Mahwah police department, many of the picnickers had dispersed, but those who remained began to feel as though they were under siege. A father and son were cut off while riding their A.T.V.s home, and the boy’s vehicle was struck by one of the rangers’. “You don’t belong on this mountain,” the boy complained.

A couple of electric-company workers investigating a low-hanging wire on the top of a nearby power line passed the German house and warned the stragglers about cops in the area. A small man standing beside a jug of wine told them that a hiker had got lost the day before. Ever since, he said, “rangers have been up here hassling us, and we’ve had enough of this shit.” He asked permission to throw rocks at the beacon on their truck as they drove away. “Have at it,” the driver said, not wanting to make trouble. Soon after, the workers crossed paths with the three rangers headed in the opposite direction, and waved.

The first ranger to arrive at the German house dismounted and ran down a slope behind the stone foundation of a barn, toward a man with a ponytail, whom she recognized as having buzzed by them on the trails shortly before. His name was Otis Mann. “No way. It’s not going to happen,” he said, resisting her attempts to pry his hands from his A.T.V. A second ranger came down the slope. Mann’s teen-age daughter got involved (“Leave my father alone!” she yelled. “What are you doing?”), and the scuffle escalated. Out came the pepper spray.

Emil Mann, the rock thrower, and a distant cousin of Otis’s, was hiding behind a tree, up the hill and out of sight. He tried to intercept the third ranger, who arrived at the clearing to the sound of screams from down below. “All this over A.T.V.s,” Emil said. “What’s wrong with you people?”

The utility workers heard two loud booms in quick succession as they approached the trailhead. A few minutes later, they encountered a frantic woman in a New Jersey State Parks Police S.U.V., who urged them to clear a path for an ambulance.

In the next half hour, a dozen police forces, from towns where teen drinking and vandalism are the principal concerns, converged on Stag Hill, shutting off the only paved road up the mountain, while, at the top, patrolmen began assembling assault rifles.

“Do they know who’s shooting?” a police dispatcher asked.

“Apparently it’s the mountain people up there.”

“Mountain people” is a euphemism for what locals used to call “Jackson Whites”—a racial slur that the referents equate with the word “nigger.” They call themselves Ramapough Mountain Indians, or the Ramapough Lenape Nation, using an old Dutch spelling for the name of the river that cuts through the Hudson and North Jersey Highlands, although suburban whites tend to think of them as racially indeterminate clansfolk. The Ramapoughs number a few thousand, marry largely among themselves, and are concentrated in three primary settlements: on and around Stag Hill, in Mahwah; in the village of Hillburn, New York, in the hollow below Stag Hill’s northern slope; and, west of Stag Hill, in Ringwood, New Jersey, in the remains of an old iron-mining complex. The settlements span two states and three counties—a circumstance with socially marginalizing consequences—but they are essentially contiguous if you travel through the woods, by foot or A.T.V.

Off-roaders in the Northeast are used to public indignities, and they track A.T.V. news on Web forums with a sense of resigned foreboding, as more of their favorite trails are closed to riding in the interest of environmental protection (“apparently we’re killing all sorts of endangered tadpoles when riding through small puddles and mud bogs”) and noise control. The Stag Hill shooting seemed to confirm their worst suspicions about how dire the situation had become. As it turned out, none of the people at the German house were armed, and the only two bullets that were fired landed in Emil Mann’s chest and left thigh. Outnumbered, unfamiliar with the terrain, and anxious from lingering visions of Harold Dennison’s arsenal, the three park rangers evidently rated the threat to their own safety more pressing than the condition of the bleeding victim. (“Yeah, we got a shitstorm coming here,” one said over his radio. “We’re on Stag Hill.”) In the commotion, another cousin, recognizing that an ambulance would never make it through the rocky trails, carried Mann to the nearest A.T.V., so that he could be delivered to the road, a mile away, where a helicopter was eventually able to land on a ball field for a medical evacuation. Otis Mann was taken to jail. At the hospital, Emil Mann was also placed under arrest. He died nine days later.