Lightning in the Blue Mountains this week has sparked 31 new fires, according to state and federal agencies.
More fires are possible given dry conditions and a forecast for thunderstorms and increasing winds through Saturday.
The new fires include nine in the Umatilla National Forest. Fire restrictions for visitors there were increased earlier this month.
Campfires are allowed only in designated campgrounds and recreation sites. Operating chainsaws is prohibited. Smoking is allowed only within enclosed vehicles, buildings and developed recreation sites or when stopped in an area cleared of all flammable material.