Fierce wildfires in the Pacific Northwest are threatening Native American lands that already are struggling to conserve water and preserve traditional hunting grounds amid a historic drought in the U.S. West.

Blazes in Oregon and Washington state were among some 60 large, active wildfires that have destroyed homes and burned through about 1,562 square miles (4,047 square kilometers) in a dozen mostly Western states, according to the National Interagency Fire Center.

It comes as extremely dry conditions and heat waves tied to climate change have swept the region, making wildfires harder to fight. Climate change has made the American West much warmer and drier in the past 30 years and will continue to make weather more extreme and wildfires more frequent and destructive.

In north-central Washington, hundreds of people in the town of Nespelem on Colville tribal land were ordered to leave because of “imminent and life-threatening” danger as the largest of five wildfires caused by dozens of lightning strikes Monday night tore through grass, sagebrush and timber.

Seven homes burned, but four were vacant, and the entire town evacuated safely before the fire arrived, said Andrew Joseph Jr., chairman of the Confederated Tribes of the Colville Reservation, which includes more than 9,000 descendants of a dozen tribes.

The tribes declared a state of emergency Tuesday and said the reservation was closed to the public and to industrial activity. The declaration said weather forecasts called for possible triple-digit temperatures and 25-mph (40-kph) winds Wednesday into Thursday that could drive the flames.

In Oregon, the lightning-sparked Bootleg Fire that has destroyed at least 20 homes was raging through lands north of the California border Wednesday. At least 2,000 homes were threatened by flames.

As an intense heat wave abated, excessive-heat warnings expired but fire weather warnings were in place for the interior of Oregon, eastern Washington, part of Idaho and the northeast corner of California due to winds and very low humidity.

The tribes are struggling with drought-caused problems. In past decades, they have fought to preserve minimum water levels in Upper Klamath Lake to preserve two species of federally endangered sucker fish that are central to their culture and heritage. Farmers draw much of their irrigation water from the same lake that’s critical to the fish. Even before the fire erupted, extreme drought in southern Oregon had reduced water flows to historic lows.