MORGAN HILL (CBS SF) — A vegetation fire just east near U.S. Highway 101 between South San Jose and Morgan Hill in Santa Clara County has consumed approximately 210 acres, Cal Fire is reporting.

The fire, dubbed the Malech Fire after nearby Malech Road, was first reported at about 3:15 p.m. Sunday. The San Jose Fire Department is helping Cal Fire fight the fire in its early stages.

READ MORE: Splash Brothers Curry, Thompson Lead Warriors Past Pistons, 102-86

The fire is in a remote area and was not threatening any structures. The fire grew to a peak of 210 acres and it was 70 percent contained as of 9:30 p.m., according to Cal Fire.

The tall dry grass on the hillside served as fuel for the flames. Cal Fire called in five air tankers to paint the hillside red with retardant.

“Retardant basically slows the fire until ground resources can get to the location to be able to contain it,” said Cal Fire batallion chief Jim Crawford. “And a lot of that is burned to an area where either helicopters can stop it or our firefighters on the ground were able to extinguish it.”

READ MORE: Friends, Loved Ones Remember Michelle Go, Killed In NY Subway Attack At San Francisco Chinatown Vigil

Two helicopters also did their part to drop water on the flames. The air support was crucial, since the terrain is very steep and there are no roads to access the fire. Ground crews had to off road and hike to the front lines of the fire.

The origin of the fire is still not clear.  Officials said the source was near a public shooting range.

When asked if the fire had been caused by someone shooting, Crawford replied, “Well, that would be an obvious observation. The range was active today at the time of the fire, but in that area there are a number of other possibilities for a cause, so we’ll do a full investigation rather than just jumping to a conclusion.”

MORE NEWS: 2 Pedestrians Killed, 2 Hurt In Crash In San Jose

The entire Bay Area is under a “red flag warning” that has been extended to Monday, brought on by a combination of hot temperatures and strong winds.