A brush fire that erupted Tuesday along the city limits of Grand Terrace and Highgrove scorched about five acres before crews completely encircled it.
The non-injury Blue Mountain Fire was reported shortly before 4 p.m. in the area of East Main Street and Mount Vernon Avenue, on the north side of Box Springs Canyon, according to the Riverside County Fire Department.
The flames were initially concentrated in San Bernardino County but crossed into Riverside County within an hour, not immediately threatening any homes or businesses.
At 6:20 p.m., the fire was declared 100% contained.
Eight Riverside County fire crews joined multiple units from the San Bernardino County Fire Department in fortifying containment lines and mopping up, according to reports from the scene.
Operations were expected to run until 10 p.m.
There was no word on what might have triggered the fire.