LEITH, N.D. — The bearded man with thinning, gray-and-bleach-blond hair flapping down his neck first appeared in this tiny agricultural town last year, quietly and inconspicuously roaming the crackly dirt roads.

Nettie Ketterling thought nothing of it when he came into her bar to charge his cellphone in an outlet beneath the mounted head of a mule deer. To Kenneth Zimmerman, the man was just another customer, bringing his blue Dodge Durango in for repairs. Bobby Harper did not blink when the man appeared in front of his house and asked him if he had any land to sell. And the mayor, Ryan Schock, was simply extending a civic courtesy when he swung by the man’s house to introduce himself.

Their new neighbor, they thought, was just another person looking to get closer to thelucrative oil fields in western North Dakotaknown as the Bakken.

But all that changed last week.

The Southern Poverty Law Center and The Bismarck Tribune revealed that the man, Paul Craig Cobb, 61, has been buying up property in this town of 24 people in an effort to transform it into a colony for white supremacists.

In the past two years, Mr. Cobb, a longtime proselytizer for white supremacy who is wanted in Canada on charges of promoting hatred, has bought a dozen plots of land in Leith (pronounced Leeth) and has sold or transferred ownership of some of them to a couple of like-minded white nationalists.

He is using Craigslist and white power message boards to entice others in the movement to take refuge in Leith, about two hours southwest of Bismarck. On one board, he detailed his vision for the community — an enclave where residents fly “racialist” banners, where they are able to import enough “responsible hard core” white nationalists to take control of the town government, where “leftist journalists or antis” who “come and try to make trouble” will face arrest.

The revelations have riveted this community and the surrounding area, drawing a range of reactions from disgust to disbelief to curiosity.

“If that man wanted to live in Leith and be a good neighbor and be decent and not push his thoughts on the people, then he could live there,” said Arlene Wells, 82, a farmer and local historian. “But to come in and want to change everything and be the big dog — no. I don’t like bulldogs.”

It is all people are talking about, in bars and in their homes, at funerals and at church. They are poking around on the Web to read Mr. Cobb’s positions for themselves. A stream of cars creep through the streets where horses occasionally trot, their passengers hoping to catch a glimpse of some action or take a peek at Mr. Cobb’s peeling, two-story clapboard home. Sheriff’s cars, too, are making more rounds.

This is not how residents wanted Leith to get back on the map. Founded in 1909, the town bustled in the middle of the century, a regional center for festivals, movies and skating. The population began slipping after peaking at 174 in 1930, but the death knell was the closing of the railroad some 30 years ago. Though the 2010 census said the population is 16, Mr. Schock puts it at 24, and the Leith Bar is the only one of the five remaining buildings on Main Street still open. Most lots are empty and overgrown, laden with high-flying grasshoppers, in this town that sits in a bowl surrounded by wheat and sunflower fields.

Mr. Cobb happened upon the community, he said, through an ad for the home he eventually bought on Craigslist. He paid a total of about $8,600 for the house and 12 plots, he said, making his first purchases in 2011. He moved here in May 2012, he said, after fleeing Canada in 2010 to avoid the criminal charges. He spent some time in Montana, before coming to North Dakota to find work in the oil patch. He said he lost his construction job last week after the story broke.

People have knocked on Mr. Cobb’s red door to offer to buy back his land and to preach the Gospel. The City Council is looking into potential ordinance or health code violations (his home has no septic tank or running water). There is a doomsday plan in place, Mr. Schock explained: If enough of Mr. Cobb’s friends move in to gain a majority that could vote out the current government, the Council would immediately dissolve the town.

Mr. Harper, Leith’s only black resident, said a lot of people approached him at his mother-in-law’s funeral on Monday to tell him they had his back.

“People told me to leave town for the weekend and they’d take care of everything,” he said.

But he and his wife, Sherrill — who found herself referred to as a “filthy race-mixing white woman” in one of Mr. Cobb’s online posts — said they were not going anywhere.

Mr. Cobb, meanwhile, seems to be soaking in the publicity and mocking it.