Fire continued to threaten the ranching community of Grouse Creek in Box Elder County as two wildfires combined to create a single blaze that has burned more than 100,000 acres in Utah and Nevada.

According to Chief Deputy Dale Ward of the Box Elder County Sheriff’s department, residents in the Grouse Creek area were ordered to evacuate on Sunday, “but then they got a few things under control and allowed them to stay in their homes. But they’ve been told to be ready to evacuate if necessary.”

The Goose Creek fire, which is believed to have been started by lightning on Thursday southeast of Jackpot, Nev., has combined with the China Jim fire, which began Saturday 13 miles southwest of Grouse Creek. The cause of the China Jim fire is unknown.

As of Monday morning, the combined blaze was only 15 percent contained, said a spokesman for the Bureau of Land Management. According to the BLM, extreme heat and twice the average fuel — grass, brush and timber — are contributing to “extreme fire behavior.”

Personnel — 38 total — from several agencies are fighting the fire, and planes have been deployed to drop retardant on the blaze.