Use of the Boiling River, Yellowstone National Park's most popular swimming hole, has been changing, and officials say probably for the better.

Long popular with locals and seasonal park employees as the spot to skinny dip and drink all night, the hot pools on the Gardner River between Mammoth Hot Springs and the town of Gardiner were overused and becoming dangerous.Two drownings in 1982 and damage to natural features in the fragile thermal area prompted park officials to change the rules.

Major changes instituted Feb. 1, 1983, were: no alcohol, no nudity and no swimming after dark.

"I'd characterize the change as from a rowdy party location to more of a family oriented recreational opportunity," said Steve Frye, North District ranger in the park. "The accident rate has dropped to virtually nothing, and use of the area by families has increased."

The Boiling River is most evident in winter, when clouds of steam rise high above the hot springs.

While the new rules may have put a damper on the rowdy crowd, use of Boiling River has not diminished.

Over the years, swimmers constructed a low wall of river rock between the hot and cold water, creating a long, narrow pool for bathers. Swimmers are no longer allowed to leave their cars along the highway above the hot springs. Instead, a parking lot next to the second bridge over the river upstream from Gardiner provides access, and a short trail along the river leads to the swimming hole.

Boiling River is open to swimmers and soakers from 8 a.m. until 6 p.m. at this time of year, but the hours change with the seasons.