A grass fire outside Atwater on Thursday afternoon slowed traffic on both sides of Highway 99.
No injuries were reported.
Capt. Jeremy Rahn of the Cal Fire/Merced County Fire Department said flames were reported just before 1 p.m. near Sycamore Avenue, parallel to the northbound lanes of Highway 99 near Applegate Road.
A total of 17 firefighters from the California Department of Forestry and Fire Protection and the Atwater Fire Department responded and extinguished the flames in about 30 minutes. Mop-up efforts took several more hours, Rahn said.
Fanned by 30 mph winds, flames eventually jumped the center divider on the freeway and burned near Bell Avenue, briefly threatening two homes, Rahn said.
Firefighters contained the flames before any damage was done or any evacuations were ordered, Rahn said.
Officer Jason Schoonhoven, a spokesman for the California Highway Patrol, said officers did not have to shut the freeway. However, vehicles were backed up to Buhach Road for about 30 minutes, Schoonhoven said.
The cause of the fire was not immediately determined.