Information about the fire near Stanley on the Sawtooth National Forest was limited, as calls to fire information officers in the region weren't immediately returned.

Chris Miller, a dispatcher with the Boise National Forest, said fire officials were sending one of their most experienced types of crews to manage containment efforts on that blaze. Some tanker aircraft had been diverted from the Idaho City fire to help.

The region is dry and has been without significant rainfall since early in the summer. In addition, some trees in the region have been damaged by pine-beetle infestations, adding to fuels, Miller said.

Stanley, located about 50 miles north of Sun Valley on State Highway 75, is sandwiched between the Sawtooth Wilderness and the Salmon-Challis National Forest and is near popular recreation areas including Redfish and Alturas lakes.

Near Idaho City, the blaze in the Sawmill Creek area about 2 miles west of the rustic seat of Boise County had spread to about 150 acres by Saturday evening. A person keeping vigil at the Sunset Mountain Lookout about 12 miles south of Lowman, as well as members of the public who were in the region, spotted smoke from the fire about 1 p.m., Miller said.

''There's a lot of slash piles there, heavy fuels. It's really dry out, and we haven't had rain in two and a half months,'' said Miller, adding that no structures have been damaged. Miller said that about 150 firefighters are working to control the blaze, using C-130 tanker aircraft stationed in Boise, as well as several helicopters, to drop fire retardant.

Crews operating bulldozers are also working to dig fire lines.

Estimated containment of the Idaho City blaze is on Monday, Miller said.

The origins of the human-caused fire are still under investigation.

Elsewhere across Idaho, wildfires were still burning on an additional 30,000 acres, according to the Boise-based National Interagency Fire Center's Web site, with most of those blazes being managed by federal firefighters to accomplish objectives such as reducing fuels to prevent a catastrophic fire.