Bulldozers worked overnight carving firebreaks around the western and northern edges of the fire. They are now working to widen that firebreak, said Big Island Fire Chief Darryl Oliveira. The southern edge of the fire was blocked by Waikoloa Road, and the fire's eastern edge was mostly contained by Mamalahoa Highway, although some areas were burning west on Mamalahoa Highway.

A fire break has also been put in place around the burn area west of the highway, Oliveira said. Two major highways through the center of the Big Island remained closed because of the fire, and Big Island Civil Defense officials asked motorists to use alternate routes.

Waikoloa Road was closed from Mamalahoa Highway to the Waikoloa Stables because of smoke hazards and because of fire crews working in the area. Mamalahoa Highway was closed from the Saddle Road to Kaiminani Drive.

The Saddle Road was reopened Wednesday for one-way traffic from Hilo to Waimea only.

"We're not calling the fire contained yet only because of the weather conditions that we're still seeing — sustained winds in excess of 20 mph," Oliveira said.

"We expect the earth to heat up, humidity to drop and wind conditions to remain constant. And we just don't feel comfortable right now calling it contained until we get past the critical part of the day, which is the hot part."

One county firefighter suffered minor injuries Tuesday afternoon while responding to the fire when the water truck he was driving ran off the Saddle Road. There was minor damage to the truck, Oliveira said.

Fire crews from the state Division of Forestry and Wildlife joined county crews and federal crews from the U.S. Army's Pohakuloa Training Area in the effort to extinguish the fire, putting a total of about 75 government firefighters on the scene.

An unknown number of private fire crews were also battling the blaze, Oliveira said. Three bulldozers were also at work on the scene, and two county helicopters and one private helicopter were continuing to drop water on the blaze, Oliveira said.