BOISE, Idaho (AP) — More firefighters are being called in to fight a fast-growing central Idaho wildfire that has been classified as one of the top priorities in the Great Basin region.

The fire about 6 miles (10 kilometers) east of Bellevue on Tuesday nearly doubled in size to 54 square miles (140 square kilometers) and started burning into the Sawtooth National Forest, a popular recreation area.

Authorities say somebody shooting an exploding target on Sunday started the fire that's burning in grass and timber. Authorities are asking for the public's help in identifying that person.

Fire spokeswoman Kim Osborn said about 150 firefighters are at the Sharps Fire with more arriving. She said they faced tough conditions Tuesday with temperatures in the 90s, low humidity, gusty winds and steep terrain.

"The fire is going to move faster," she said. "It's going to make it tough on firefighters. We'll see what good work they can get done today."

Firefighters already saved a ranch, Osborn said, and no structures have been lost. Some residents on the Little Wood Reservoir have been told to evacuate, and area closures are in place. The fire was not contained Tuesday.

Nine significant fires were burning in the state on Tuesday. The largest was the 162-square-mile (420-square-kilometer) Grassy Ridge Fire burning in grass and brush in eastern Idaho. Nearly 400 firefighters had the blaze 88 percent contained, evacuations have been lifted and lines have been built entirely around the fire.

In west-central Idaho, officials on Tuesday estimated the Rattlesnake Creek Fire burning in grass and timber at about 6 square miles (16 square kilometers). About 530 firefighters are trying to control that human-caused blaze threatening homes in Pollock, Pinehurst and Whitewater Wilderness Ranch Estates. Residents there have been told to be ready to evacuate if needed.

Area closures are also in place, including portions of the Nez Perce-Clearwater National Forests and Payette National Forest. Access to some of the Hells Canyon National Recreation Area is also closed. The fire is about 25 percent contained, but officials on Tuesday said that could increase with better conditions.

"We have a little bit of cloud cover coming in, and the smoke across the region is doing a lot to dampen fire activity," said fire spokeswoman Kary Maddox. "We have high hopes for today's operations."

U.S. Route 95 remained open through the area on Tuesday, but motorists can expect smoke and traffic congestion. Motorists are advised not to stop along the highway corridor that's being used by firefighters.