U.S. Forest Service spokesman Mick Mueller said the four structures were summer homes permitted on Forest Service land, which were adjacent to the Wenatchee Ranger Station.
Mueller said the fire is reported to have been caused by people, but it remains under investigation.
Officials say the public should avoid the area because of heavy fire traffic.
Fire crews on Saturday were mopping up and looking for hot spots with infrared cameras.
More Northwest Headlines
Stanwood man pleads guilty to stealing from Swinomish tribe GOP lawmakers want Washington to look at Planned Parenthood Poll: Just 30 percent inclined to re-elect Gov. Inslee Death penalty dropped from Carnation killings trial Salvation Army sets up charging ports for Portland homeless Spokane criminal faces 30th felony charge Police: Couple charged in Seattle dog fighting operation Activists rappel off Oregon bridge to stop Shell icebreaker
Our new comment system is not supported in IE 7. Please upgrade your browser here.