Larimer County, CO (CNN) - The High Park fire, burning northwest of Fort Collins, Colorado has scorched more than 52,000 acres.

Crews are attacking the blaze on the ground and helicopters are fighting it from the air.

More than 1,300 personnel are battling the fire and setting back-burns to slow its progress.

About 70 percent of the wildfire is burning on federal land.

It's 10 to 15 percent contained.

CNN