Sen. Byron Dorgan believes that adding scenic North Dakota Badlands to the National Register of Historic Places will restrict land use and has told the U.S. Forest Service that he will attempt to block the nomination.

"I've told them, essentially, 'Knock it off,'" Dorgan, D-N.D., said Friday.

A historic designation in an area where Theodore Roosevelt ran a short-lived cattle ranching business more than a century ago would violate an agreement about its use made when the government bought the property, Dorgan wrote in a stern letter to Forest Service Chief Thomas Tidwell.

"I was happy to pass legislation in Congress that resulted in the acquisition," Dorgan wrote in the September letter. "But further designations of this land would violate the agreement.

"I will oppose this nomination," Dorgan wrote.

The National Register of Historic Places is the federal government's list of properties it considers worthy of preservation and recognition. The proposal for the historic designation includes about 12,000 acres of land around the Theodore Roosevelt National Park Elkhorn Ranch and the Elkhorn Ranchlands, a private ranch that the Forest Service bought two years ago.

The National Park Service is backing the Forest Service's proposal.

State and local officials believe the historic designation would add another layer of bureaucracy to the Badlands and could prevent oil and gas development, lessen the amount of land open for grazing and stymie plans for a proposed bridge over the Little Missouri River.

Sharon Small, a Forest Service spokeswoman in Bismarck, said the designation does nothing more than recognize the area's historic value.

"Basically, it's just highlighting the area," she said. "It won't place any further restrictions on the area."

Small said the Forest Service is moving forward with its nomination, despite the opposition, because it is legally compelled to nominate historic districts.

"The only thing they are obliged to do is keep their word," said Dorgan, who helped broker the deal and pushed legislation for the purchase of the land in 2007.

The federal government paid $4.8 million and conservation groups contributed $500,000 for the purchase, and the Forest Service promised to keep allowing grazing and other activities, including oil and gas development, on the land.

The Forest Service's acquisition of the historic ranch has been mired with problems since the deal was completed. A Montana man claims he controls mineral rights beneath the ranch and has threatened to mine gravel unless the Forest Service pays him.