The Gorgonio Fire south of Banning was fully contained Monday and was expected to be out by Monday night, authorities said.
The fire started just before noon Saturday. No structures were threatened and no evacuations required, said Riverside County Fire Department spokeswoman Jody Hagemann.
After re-mapping the fire zone, firefighters downsized the damage estimate from 650 to 510 acres, she said.
On Sunday, 412 firefighters battled the blaze, along with 17 hand crews, two helicopters and seven air tankers, Hagemann said. Containment lines were carved around the blaze, and firefighters expect to have all remaining hot spots out by 6 p.m. Monday, she said.
Highway 243 between Idyllwild and Banning was reopened Sunday, but motorists were urged to use caution and yield to fire trucks.