A grass fire in the Cuyama Valley threatened at least one structure and had blackened some 50 acres on Sunday before crews stopped the forward progress of the flames.

At approximately 5:10 p.m., personnel from the Santa Barbara County Fire Department and the Los Padres National Forest responded to the incident on the 1500 block of Wasioja Road. 

Multiple aircraft including tankers and helicopters also were dispatched to help in fighting the blaze.

The fire was spreading at a moderate rate while burning in grass and woodlands, according to emergency dispatch reports.

Firefighters estimated the Wasioja Fire could grow to 200 acres and was less than 2 miles from the forest boundary.

Crews stopped the fire’s forward progress at approximately 7:45 p.m. and reduced their estimate the fire’s size from the previous 70 acres.

The fire sparked as the Cuyama Valley and other interior areas of Santa Barbara County remained under an excessive-heat warning expected to continue through Thursday night, according to the National Weather Service. 

The warning noted “dangerously hot conditions,” with temperatures of 100 to 110 degrees expected each day. The areas will experience warm overnight low temperatures — generally in the 70s and lower 80s.

Sunday’s top temperature in the Cuyama Valley hit 100 degrees, with triple digits expected through Thursday. 

One tanker en route to the Wasioja Fire ended up being diverted after spotting a different incident while on its way to the Central Coast, according to emergency dispatch reports.

The cause of the fire remained under investigation.

The fire reportedly did not affect Highway 166 traffic.