Two inland Mendocino County fires were largely quelled by late Monday afternoon but state and local firefighters were getting no reprieve as a third erupted in southern Lake County.

The first fire, dubbed the Grade fire, broke out along highway 101 Sunday afternoon about 20 miles northeast of Ukiah and quickly spread to steep, rugged terrain, hampering firefighting efforts. It burned an estimated 900 acres and forced evacuation of nearly two dozen homes in a Redwood Valley subdivision. It was 30 percent contained by 9 p.m. Monday.

According to Cal Fire, 433 personnel were involved along with 40 engines, 16 bulldozers and six water tenders. One injury was reported, but no details were available Monday night.

The cause is under investigation but the CHP’s Ukiah traffic incident website suggested it may have started as a car and trailer fire. Motorists captured video of a truck with its engine compartment in flames.

As firefighters gained control of the Grade fire, a second ignited around noon in the Cow Mountain Recreation Area east of Ukiah.

It began at a gun range and quickly spread to 10 acres, fire officials said.

Firefighters and aircraft from the Grade fire were diverted and quickly had the new fire under control.

The third fire broke out in Lake County just before 3 p.m. near Highway 29 and Agua Dulce, 3 miles south of Lower Lake, which was devastated by an arson fire last year. Named the Murphy fire, for its proximity to Murphy Springs, it was first reported at 2:36 p.m.

By late Monday afternoon it had burned an estimated 40 acres, shutting down Highway 29 near Hofacker Lane, but not prompting any evacuation orders, Cal Fire said. At 5:45 p.m., Cal Fire reported it was 50 percent contained and its forward spread stopped.

“It’s looking better than it did just a bit ago,” said Cal Fire Captain Tiffany Mercado. “A lot of the aircraft on it have done a lot of work, and put some retardant line around it.”

About 50 to 100 structures are immediately threatened, she said.

The steep terrain and brush made the fire difficult to tackle.

Southern Lake County was decimated by the massive Jerusalem, Rocky and Valley fires in 2015. The three fires burned more than 170,500 acres and 2,000 structures and killed four people.

Staff Writers Paul Payne and Christi Warren contributed to this report. You can reach Staff Writer Glenda Anderson at 707-462-6473 or glenda.anderson@pressdemocrat.com. On Twitter @MendoReporter.

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