UPDATE: Crews are getting closer to fully containing the South Valley Fire burning near Dufur.
Crews expect to have the blaze contained by Friday.
It has burned more than 20,000 acres and is 65 percent contained.
PORTLAND, Ore. (AP) -- A new blaze in north-central Oregon nearly tripled in size overnight.
The South Valley Fire near the town of Dufur, about two hours southeast of Portland, spread to more than 14,000 acres early Thursday.
The Oregon State Fire Marshal's Office says dozens of structures are threatened -- some have burned -- and at least 400 people have been told to evacuate.
The fire, caused by humans rather than lightning, began Wednesday afternoon. By nightfall, Gov. Kate Brown declared it a conflagration, which authorizes the fire marshal to mobilize state-wide resources.
It's the third major wildfire in the area this summer. One scorched 125 square miles (323 square kilometers) and killed a man.
After an unusually warm July, firefighters caught a break with cooler temperatures Thursday.