HELENA -- Missoula industrialist Dennis Washington is donating a conservation easement on 240 acres of prime recreational land along the scenic Smith River, where thousands of people float each year, state officials said Friday.

"It's going to make one of (Montana's) crown jewels even better," said Mike Halligan, director of government relations for Washington Corps.

"This is an extraordinarily generous gift for those of us who seek to get on Montana's rivers," said Attorney General Mike McGrath, who estimated he's floated the Smith River at least a dozen times. Washington's generosity "will guarantee countless opportunities for Montana recreationists" for generations to come, he said.

McGrath called the scenery on the Smith River "some of the most magnificent" he's ever seen.

Gov. Brian Schweitzer thanked Dennis Washington and his wife, Phyllis, Washington and Washington Corps., "for this extraordinary gift." The Washingtons have been "wonderful neighbors and leaders" in Montana, he said.

Dennis Washington is a self-made billionaire who is also known for his philanthropy in Montana.

"In a state blessed with so many natural treasures, the Smith River is one of Montana's crown jewels," Schweitzer said.

The gift, valued at up to $1.5 million, will add nearly one-quarter of a mile of public riverfront in Cascade County to the 59-mile float that meanders through limestone canyons. The land is on both sides of the Smith River, and the Deep Creek tributary joins the Smith River on the parcel.

The Department of Fish, Wildlife and Parks plans to add two more boat camps to the existing 27 boat camps and 52 camping sights along the river.

It was McGrath who approached Washington Corps. last year about the possibility of donating a conservation easement on the river.

Halligan said Washington Corps., owned by Dennis Washington, have a strong culture that emphasizes corporate civic responsibilities.

"As we analyzed our options, it became clear to us that the highest and best use of property was in the public domain in perpetuity," Halligan said.

The donation will be presented to the Fish, Wildlife and Parks Commission for its formal endorsement at its June 14 meeting in Columbus.

Washington acquired the property when he bought Arco's property, formerly the Anaconda Co.'s land, in 1986.

Schweitzer said the Anaconda Co. originally bought this land in the 1920s or 1930s because of the large quantities of carbonate and calcium carbonate available. The Anaconda Co. needed these materials for its refinery in Great Falls.

The company planned to level the mountain to mine this material, crush it and push it into the Smith River as slurry. It would travel down the Smith River before joining up with the Missouri River. Anaconda Co. employees would be able to recover the carbonate and calcium carbonate and put it to use in the refinery.

"Fortunately, they didn't get around to it," Schweitzer said.

Schweitzer recently took a helicopter ride over the property and floated down the Smith River in a torrent of rain last month.

Fish, Wildlife and Parks Director Jeff Hagener said the department is in the process of updating its Smith River management plan. The earliest the two new boat docks can be put in will be next year.

The Smith River is the only river in Montana that requires permits for public and private use of the river.

Smith River permits are highly coveted. For the 2007 season, 5,012 people applied for permits, and the department issued 844 permits. Last year, 4,736 individuals floated the river, including both private and outfitted floaters.