Pomeroy, Wash. ? Fire crews are contending with summer heat and rough terrain as they fight to encircle a 49,000-acre wildfire, the largest in the Lower 48 states.

The fire in southeastern Washington has destroyed more than 100 homes and more than 100 outbuildings about 15 miles south of Pomeroy. It was second in size only to an 82,000-acre blaze in Alaska.

Fire officials estimated the blaze was 75 percent contained Monday but could not say when it might be brought under control.

The National Interagency Fire Center said 28 large fires totaling 290,000 acres were active Monday in Alaska, Arizona, Arkansas, California, Idaho, Minnesota, Montana, Nevada, Oregon and Washington. So far this year, wildfires have charred 5.89 million acres nationwide, compared with 5.95 million acres at the same time last year.