By Laura Zuckerman
SALMON, Idaho (Reuters) - Evacuation orders were lifted on Thursday for 600 residents of an affluent northern Idaho resort area where a wildfire destroyed six upscale homes and burned within a mile of where the U.S. Navy tests submarine acoustics.
The so-called Cape Horn fire was 40-percent contained on Thursday, the same day Idaho Governor C.L. "Butch" Otter toured burned areas adjacent to a mountain lake known for premier boating, water-skiing and fishing opportunities.
The blaze, the cause of which is under investigation, broke out Sunday in fir and spruce forests above Lake Pend Oreille, whose shores are clustered with expensive homes and luxury condominiums.
The fire was no longer considered a serious risk to a transmission line the U.S. Navy depends on for electric to power its Acoustic Research Detachment fronting one of the nation's largest lakes near the tiny resort town of Bayview.
Fire managers on Thursday reduced the estimated size of the fire to 1,155 acres (467 hectares) from a high of an estimated 2,000 acres (809 hectares) after a second overnight infrared mapping flight.
Hundreds of firefighters backed by bulldozers and aided from the air by helicopters have worked to contain the blaze as temperatures and winds declined in a usually wet region short on rainfall this year, said federal fire information officer Norm Rooker.
Rooker said fire bosses were "guardedly optimistic" that the blaze would be fully contained as early as next week.
"But Mother Nature always has the last bat," he added.
The Cape Horn fire was one of 33 large fires burning in Western states, where a long-standing drought has left forests, river valleys and rangelands tinder dry.
Rooker said climate changes bringing less moisture to the region and warmer temperatures accelerating melting of spare mountain snow have prompted predictions by U.S. fire officials that the season would see large and possibly more damaging blazes.
Alaska has seen 24 large fires that have burned nearly 1.2 million acres (485,623 hectares), according to the National Interagency Fire Center.
In Oregon, firefighters resumed the battle on Thursday against the lightning-sparked Corner Creek fire after pulling back due to thunderstorms a day earlier, a fire official said.
The 28,800-acre (11,655-hectare) blaze, which destroyed a hunting cabin and prompted closures of campgrounds and public lands, was 50 percent contained.
With high heat and more lightning forecast, crews were preparing for the possibility that it could grow, an incident commander said Thursday.
(Reporting by Laura Zuckerman in Salmon, Idaho; Additional reporting by Courtney Sherwood in Portland, Oregon; Editing by Eric M. Johnson and Sandra Maler)