A driver on I-90 spotted the fire just before noon and called it in.
Fire crews assembled in the area near 444th Ave SE and Mt. Si Road, said Bud Backer, Deputy Chief for Eastside Fire & Rescue. The fire spread into the wilderness area, but by 5 p.m. it was 50 percent contained.
Six local fire engine companies responded to the fire before handing it over to firefighters from the Department of Natural Resources. A DNR helicopter later arrived and began dropping water from its 260 gallon bucket.
Only a small portion of the fire is accessible from a road, Backer said, adding the fire is growing and moving uphill away from that road.
Crews have been able to create a hose line around the two acre fire. The plan is to monitor it overnight, at which point more DNR crews will arrive to mop it up.
So far there are no plans to evacuate any nearby homes, but that hasn't calmed the nerves of people who live in the area.
"I just want them to douse it so its all gone," said Cheryl Thompson. "We've been worried about this all summer. Because it's been so hot and dry, we've been worried about this."