This story was last updated at 9:54 a.m. Monday.

Firefighters continued Monday to battle a two-alarm vegetation fire burning in the mountains north of Lake Cachuma, about five miles east of Highway 154.

The blaze, which blackened an estimated 100 acres, broke out shortly after 10:30 p.m. Sunday off Happy Canyon Road.

(Fire officials reduced the size of the blaze from an earlier estimate of 150 acres.)

Containment was at 50 percent by midmorning.

The Santa Barbara County Fire Department sent a full vegetation fire response, assisted by crews from Los Padres National Forest.

On Monday morning, the U.S. Forest Service was taking over management of the fire, which is burning in the national forest near the shooting range on Happy Canyon Road.

Fire Capt. Daniel Bertucelli. said the fire was burning through very dry, brittle grass with a moderate rate of spread. Winds were reported to be 10-15 mph in the area.

No structures were threatened and no injuries have been reported.

At 8:30 a.m., U.S. Forest Service spokesman Andrew Madsen told Noozhawk that the forward progress of the flames had been stopped.

Air tankers were ordered but had not been dispatched to the blaze, Madsen said.

The fire was reported burning away from Lake Cachuma, toward the Goat Rock area, and bulldozers were trying to prevent an uphill run toward Cachuma Peak.

Battalion Chief Chris Childers told Noozhawk at the scene early Monday that firefighters and bulldozer crews expected to have the blaze corralled by daybreak — as long as the winds remained light.

No wind events were in the overnight National Weather Service forecast, but wind gusts as high as 15 mph were possible Monday afternoon. Daytime temperatures in the upper 80s are expected Monday.

Childers said a lack of water sources in the area was a hindrance for crews running extended hose lines around the fire.

Fire officials initially had a difficult time locating the blaze, and were concerned there could be more than one fire.

They eventually determined that what was dubbed the “Range Incident” was the only one.

The county sent six engines, bulldozers, a water tender and a hand crew to the site.

Additional information was being relayed to firefighters from a U.S. Forest Service camera on Santa Ynez Peak.

— This story includes reporting from Noozhawk contributing writer Ray Ford. Executive editor Tom Bolton can be reached at .(JavaScript must be enabled to view this email address) . Follow Noozhawk on Twitter: @noozhawk, @NoozhawkNews and @NoozhawkBiz. Connect with Noozhawk on Facebook.