The Muir Fire between Stinson and Muir beaches in Marin County is holding at 58 acres and 50 percent containment as of Friday morning, the Marin County Fire Department said.
State Highway 1 is expected to remain closed until 6 p.m. Friday.
The Muir Fire burning coastal brush and grasslands on a hill along the Pacific coast was reported at 10:45 a.m. Thursday just north of the Slide Ranch at 2025 Highway 1.
The fire is Marin County’s largest this year. Attacks from air, with water and retardant, were crucial in preventing the fire’s spread, the Marin County Fire Department said. Offshore breezes also pushed the flames toward the ocean instead of to Mount Tamalpais to the east.
Sixteen fire agencies in the county responded to the fire. The cause is unknown.