Mike Marvin was 20 when he bought his first buffalo. He didn't have any experience. He just thought the animals were cool. He liked their big woolly heads and their horns, and their connection to the American west. That was 44 years ago.

"Back then, buffalo ranchers were fools or dreamers," he said. "There wasn't really a business plan."

He found a buffalo rancher in South Dakota who would sell him a bull and some breeding stock. Mike's cousins own the Marvin Windows company, one of the area's largest employers. He's not involved in the window business, but his cousins agreed to ship his first few buffalo back to Warroad, on Minnesota's northernmost border, in a window delivery truck.

"I was young and I didn't have any commitments," he said. "It just sort of went from there."

Marvin still runs one of the northernmost buffalo ranches in the lower 48. Most of the time, his herd of 57 buffalo roam nearly 300 acres of pasture just outside of Warroad.

Mike Marvin bought his first buffalo when he was 20 years old. Over the last 44 years he's built miles of fence and been trampled once. John Enger | MPR News

Marvin makes his money selling calves to a feedlot in southern Minnesota. He said there were some bad years in the early 2000s, but the buffalo market is getting better. But that's not really why people raise buffalo.

Marvin drove around the pasture, surveying the herd from his Chevy Silverado.

"It's called safety," he said as the herd jogged out of the way of the truck.

"I've only been hurt once, thank goodness," he said. "I had some animals in a corral. They ran at me. My leg came out of my hip socket. They hit me pretty good."

Marvin edged up to a massive one-ton bull. It's head is the size of small refrigerator. A woolly beard hangs down to its knees and horns curl to sharp points. It's a wild and romantic creature, Marvin said. That's why he got into the business, but it's also why he'll get out one day.

Buffalo are not domesticated, like beef cattle. It takes special heavy duty fencing to keep them in. Over the last 44 years, Marvin has carried thousands of railroad ties and strung miles and miles of barbed wire. It's hard work, especially with a dislocated hip.

Calves are sold just before winter, so late this fall they were all grouped together in a large corral. John Enger | MPR News

Even the best fence doesn't always work.

"If you make a mistake on your fence, or you don't close the gate, you have a problem," he said. "The problem is, they're out. It's kind of the worst phone call you can get."

The sun-bleached skulls of buffalo are scattered around Mike Marvin's ranch. John Enger | MPR News

Marvin got that phone call twice in his long career. Once, when he was new to buffalo ranching he forgot a gate open. A state trooper called him just before midnight. His buffalo were walking around on the highway.

Twelve years ago they escaped again — this time running eight miles into the nearby state forest, where they evaded capture for a full week. Finally, one of Marvin's childhood friends tracked them down with a high-powered rifle. They set up floodlights and butchered into the night.

"It was very exciting for everyone but the rancher who owned them," Marvin said. "A few more phone calls like that and I'm done."

Some days, Marvin feels like he'll keep ranching for many years. He enjoys his easy access to buffalo roasts. On other days, his body hurts from moving all those railroad ties, and from getting trampled. On those days, he says, he thinks hard about retirement.