A reporter for a local newspaper, The Missoulian, noticed the trademark symbol next to “The Last Best Place” in an advertisement for Mr. Lipson’s resort and wrote an article about it. He wrote that Mr. Lipson, filing under one of his businesses, The Last Best Beef, had tried to gain exclusive rights to the slogan  not only to market his resort, but for other businesses, including jewelry, kitchenware and a line of clothing that includes hats, underwear and lingerie.

Image William Kittredge came up with the phrase and used it as the title of a 1988 anthology of Montana writers that he helped edit. Credit... Peter DaSilva for The New York Times

Among those who denounced Mr. Lipson for claiming the phrase was Gov. Brian Schweitzer and Senator Max Baucus, both Democrats, as well as Mr. Kittredge. “Senator Baucus joins Montanans in their outrage,” said Barrett Kaiser, a spokesman for the senator. “This is Montana’s phrase.”

Mr. Kittredge said he was “delighted” that Congress had acted to protect his phrase and wanted everyone to be able to use it.

“It was intended as a gift to the people of Montana,” he said. “Montana wasn’t doing well economically at that time, and we’re out in the sticks, and it was a way to help Montanans feel connected to the greater world.”

In 2004, Senator Conrad Burns, a Montana Republican, made the first legislative attempt to stop Mr. Lipson from obtaining a trademark for the term, but Mr. Lipson filed a lawsuit against the Patent and Trademark Office to overturn that language. Mr. Lipson won, but the case was overturned by the Fourth Circuit Court of Appeals.

Mr. Baucus introduced a bill with stronger language after the first court decision, effectively banning the Department of Commerce from issuing a trademark for the phase “The Last Best Place.” The measure passed, but because it was part of a budget bill, it had to be reintroduced every year.