GROVELAND, Calif. – Firefighters battling the giant wildfire burning in the Sierra Nevada added a California National Guard Predator drone to their arsenal Wednesday to give them almost immediate views of any portion of the flames chewing through rugged forests in and around Yosemite National Park.

The MQ-1 unmanned aircraft being remotely piloted hundreds of miles away quickly alerted fire bosses to a new flare-up they otherwise wouldn’t have immediately seen.

“They’re piping what they’re seeing directly to the incident commander, and he’s seeing it in real time over a computer network,” said National Guard Lt. Col. Tom Keegan.

Previously ground commanders relied on helicopters that needed to refuel every two hours.

The 12-day-old Rim Fire continued to grow, expanding to 292 square miles, and containment remained at 23 percent. But increasingly confident fire officials said they expect to fully surround it in three weeks, although it will burn for much longer than that.