BLY, Oregon (AP) — Firefighters in Oregon reported good progress in the battle against the nation’s largest wildfire, while authorities canceled evacuation orders near a major blaze in Northern California.

Containment of the Bootleg Fire in remote southern Oregon was up to 74% on Sunday. It was 56% contained a day earlier.

“That reflects several good days of work on the ground where crews have been able to reinforce and build additional containment lines,” fire spokesman Al Nash said Sunday.

The blaze has scorched over 646 square miles (1,673 square kilometers) since being sparked by lightning July 6 in the Fremont-Winema National Forest.

California’s Dixie Fire covered nearly 383 square miles (992 square kilometers) in mountains where 42 homes and other buildings have been destroyed.

It was 32% contained Sunday, and evacuation orders and warnings were lifted for several remote areas of Butte and Plumas counties. But authorities warned that with unpredictable winds and extremely dry fuels, the risk of flare-ups remained high.

The cause of the blaze, which ignited July 13, was still under investigation.

In Montana, a wind-driven wildfire destroyed more than a dozen homes, outbuildings and other structures, authorities said Sunday. Evacuations were ordered after flames jumped a highway and moved toward communities near Flathead Lake in the northwestern part of the state.

Crews also battled major blazes in northeast Washington and northern Idaho.

Nearly 22,000 firefighters and support personnel were battling 91 large, active wildfires covering 2,813 square miles (7,285 square kilometers) in mostly western states, the National Interagency Fire Center said.

A historic drought and recent heat waves tied to climate change have made wildfires harder to fight in the American West. Scientists say climate change has made the region much warmer and drier in the past 30 years and will continue to make weather more extreme and wildfires more frequent and destructive.

The U.S. Drought Monitor reported last week that while a robust monsoon has delivered drought-easing rainfall to the Southwest, critically dry conditions persist across Northern California and the Northwest, where there has been an expansion of “exceptional drought,” the worst category.

Dry conditions and powerful winds made for dangerous fire conditions in Hawaii. A wind advisory was issued Sunday for portions of Lanai, Maui and the Big Island.