Brian Pope reaches a cruising mile-pace of 5:45, running along an old railroad bed in lushly wooded trails, when he hears a rifle shot. The six-foot-three, 145-pound Pope has run these trails daily since he came to Oxford from Jackson in 1981 for college at Ole Miss. On a calm, late morning, he moves effortlessly and efficiently down the abandoned tracks that once carried passengers south on the Mississippi Central Line to New Orleans. On each side of him, there is land claimed by deer hunters, land that William Faulkner used as the inspiration for his fictional Yoknapatawpha County.

As Pope reaches a clearing in the woods, a hunter and his wife emerge on an ATV four-wheeler, yelling for him to stop. Pope quickens his pace.

When Pope keeps running, the man fires a warning shot. Pope finally stops his watch and then himself and turns back to confront the shooter and his wife.

“What are you doing out here on private land?” the hunter asks as he points the rifle at Pope.

“This is university-owned property,” Pope replies.

“No, it’s not,” says the hunter, moving off the four-wheeler. “I’m going to kick your scrawny ass if you don’t get going.”

“Okay, let’s go, show me what you got,” says Pope, who uses his right hand to push the barrel of the rifle away from his torso. The hunter shows temerity by taking a step backward. “Just what I thought, Pope says. “You’re just a coward with a gun.”

The hunter hollers obscenities as Pope re-starts his watch and resumes his run back toward town.

Pope protects his freedom to run as fiercely as a sportsman does his right to hunt and kill game. On these trails, he has had frequent encounters with hunters. “I don’t like people messing with me when I’m running,” he says. “That’s my protective space.”

Since the altercation three years ago with the hunter, Pope, now forty-five, has led the effort to preserve some of the five-hundred-and-fifty-acre plot of land for runners and mountain bikers. He’s also directed a successful campaign to block the city from paving the dirt trails. “I’ve always been protective of those trails,” he explains. “It’s really the only off-road place to run in town.”

For years, Pope has been the First Runner of Oxford and, because of his singular devotion to the sport, an enigma to his neighbors, friends, and training partners.

He leads a monastic life, and whatever it is that he summons to make him run twice a day—his Baptist upbringing or deep withdrawal from society to make a closer connection to his purpose—his achievements are remarkable.

On back-to-back weekends in 2004, he set American Masters records in...