PINEDALE - Firefighters were battling a small blaze late Monday near the Big Sandy River in the Bridger-Teton National Forest, site of the recently completed Rainbow Family gathering, according to U.S. Forest Service officials.

The fire - dubbed the Gathering 2 Fire - had burned just under an acre of dead trees, officials said.

Bridger-Teton spokeswoman Mary Cernicek the cause of the fire was determined to be an "escaped campfire," but she did not know if the fire started in a Rainbow Family campsite. She said there were still several thousand Rainbows in the forest who are slowly leaving the Big Sandy area.

Cernicek said as a precautionary measure, the agency ordered the immediate evacuation of two of the smaller camps near the Rainbows' summer retreat site. The Rainbow event culminated Friday with the group's annual circle of prayer.

"It's just the peripheral camps we evacuated, and a lot of them were leaving anyway… It was probably just 50 people or so we told to go," Cernicek said. "And (in most cases) we didn't really have to inform them. The fire was putting up quite a bit of smoke because that wood is dead and down."

The fire was reported near the Bear Trap Meadows on the border between Bureau of Land Management lands and the Bridger-Teton National Forest. The site is about 31 miles southeast of Boulder near the Dutch Joe Guard Station in Sublette County.

Firefighters were using a specialized helicopter from Idaho to combat the blaze Monday evening. Officials said the fire was moving east.

On June 23, as Rainbow Family members were beginning to move into the area, a fire burned about a quarter of an acre of wild grass and a tree stump near the Dutch Joe Guard Station before the blaze was extinguished. Its cause was not determined.