Flames that raced through about 3,500 acres of San Gabriel Wilderness Area brush slowed to a near stop Monday, but more than 1,000 firefighters were warned that erratic winds from mountain thunderstorms could whip them up again.
For the time being, however, rising humidity and generally low winds eased the situation both there and in the Lytle Creek area near the Cajon Pass, where nearly 600 acres had been burned by another blaze.
The fire in the Angeles National Forest north of Azusa began Sunday afternoon, when barbecue coals were dumped into dry grass at a picnic area just west of San Gabriel Canyon Road, a U.S. Forest Service spokesman said.
Because there are no improvements in the designated wilderness area, no structures were damaged or threatened. However, by the same token, there are no roads, leaving crews to struggle across rough terrain in an effort to get a line around the fire.
The blaze was only 10% contained by Monday afternoon. Fire service spokesman Bob Swinford said containment was tentatively predicted for 6 p.m. Wednesday, but that would depend on whether thunderstorms in the area made mischief.
If the blaze continued to burn westward, Swinford said, it could threaten watershed growth in the Devil's Canyon drainage area leading down to the west fork of the San Gabriel River. Brush there has not been burned for 62 years, he said.
San Gabriel Canyon Road (California 39) will remain closed about 15 miles north of Azusa for at least two days, according to the California Highway Patrol. Nearly 10,000 campers, hikers and fishermen were evacuated from the west fork area south of Crystal Lake on Sunday.
Aiding the hand crews were 11 aerial tankers, working out of Fox Field in Lancaster, and four helicopters.
In the meantime, U.S. Forest Service officials anticipated containment of the Lytle Creek fire northwest of San Bernardino by Monday evening, after it burned about 560 acres. Some businesses and homes were threatened briefly, but the only loss reported by Monday were some power poles.
Nearly 800 people were battling that fire, and they too were alerted to the possibility of renewed trouble, because of thunder and lightning storms in the region.
Roads were closed to all but residents of the area.
Cause of the fire was being investigated.