LAS VEGAS (KLAS) — The Wildcat fire in Elko County has grown by about 50% since Friday, now covering more than 21,000 acres.

It’s the largest wildfire so far this year in Nevada, burning near the Jarbidge Wilderness. Some structures are threatened by the fire, officials said, including an old Forest Service Guard Station in the area.

Information released today by the U.S. Forest Service indicates there are 312 personnel on site fighting the fire. The fire is 55% contained.

The Wildcat fire grew dramatically late last week after it was first reported on Wednesday about 40 miles from the town of Wells. Photos released by the Forest Service show aircraft attacking the fire with loads of fire retardant. The fire is burning grass and sage.

Also on Monday, Bureau of Land Management officials said the Becky Peak fire in White Pine County is now fully contained after burning 5,989 acres — the second-largest fire so far this year in the state.

The Becky Peak fire is in the Schell Creek Range, about 50 miles north of Ely.