Crews are trying to keep a wildfire from spreading beyond the Elkhorn Drive Scenic Byway near Anthony Lakes and potentially threatening structures.

The Bear Butte fire has burned an estimated 450 to 500 acres, and is 10 percent contained, said Willie Crippen, a fire management officer for the Wallowa-Whitman National Forest. That’s about half the size estimated Friday night. Crippen said fire officials refined the estimated after flying over the fire in a helicopter Saturday morning. Dense smoke on Friday night made it difficult to gauge the size of the blaze, Crippen said.

Officials also have not determined the cause of the fire. On Friday night the Forest Service deemed the fire, which was reported about 2 p.m. Friday, as human caused, but that was an error, Crippen said. It might have been human-caused, but fire investigators were not able to survey the point where the fire started because it grew so quickly, he said. There has not been lightning in the area for several days.

The fire grew rapidly Friday, fueled by gusty northwest winds, hot temperatures, low humidities and dense stands of subalpine fir trees. Fire tends to spread quickly through subalpine firs, which have limbs that grow close to the ground, and sap that contains flammable oil.

Crippen said the crews working on the fire Saturday — including 10 engines, four bulldozers and multiple helicopters — focused on confining the fire on the north side of the Elkhorn Byway, south of the ridge between Antone and Indian Creeks, and east of the area burned during the 1990 Bear fire. The fire has not crossed the ridge and burned into the Indian Creek drainage, he said. Crews have conducted burnouts between the Byway and the main fire to reduce the amount of fuel available. The fire has been moving generally east/southeast, away from Anthony Lakes.

Crippen said the active fire is all north of the Byway, roughly between the Baker Valley Scenic Overlook on the east, and the Van Patten Lake trailhead on the west.

“It’s long and narrow,” he said.

On Friday the fire prompted the closure of Anthony Lakes Mountain Resort, the cancellation of today’s Mountain Bike Festival, and the evacuation of the campgrounds in the Anthony Lakes area as well as the Floodwater Flats summer cabins just northeast of Anthony Lakes. Baker County has also issued evacuation warnings, but not any required evacuations, for residents along the Elkhorn Byway from where the highway leaves Baker Valley, and the Wallowa-Whitman boundary. The Byway is closed between the Wallowa-Whitman boundary on the east side of the Elkhorns, to the North Fork John Day campground to the west.

Crippen said winds calmed overnight and there was little wind on the fire as of noon Saturday.

“It’s going to be real telling this afternoon, when we started getting wind on it,” he said Saturday.

Peter Johnson, manager of Anthony Lakes Mountain Resort, said an employee who was working on a mountain bike trail Friday afternoon saw smoke from the fire, and Johnson reported it to the Forest Service.

Crippen said contract crews have been cutting and piling trees along the Byway in the Anthony Lakes area this summer, but he said no work has been done for the past several days due to the increasing fire danger. Crippen said no work had been done in the area where the fire started on Friday.

The fire is burning near the site of a 1990 blaze that killed most of the trees in an area near the headwaters of Indian Creek. Johnson said the fire appeared to be burning very close to the area burned in the 1990 fire. The area around Bear Butte also has large acreages of dense lodgepole pine trees that grew following the 20,000-acre Anthony fire in 1960.

Information about the Bear Butte fire is available at https://inciweb.nwcg.gov/incident/article/5464/37518/

People who had to evacuate can click on the “announcements” tab to get updates on when road closures are lifted so people can retrieve any belongings.