(Butte County, CA) — The Park Fire, burning across more than 427-thousand-acres in Lassen National Forest, remains 34-percent contained as of late Thursday. The blaze, which has been exacerbated by hot and dry conditions, is spreading northeast.

Forecasters predict cooler temperatures and higher humidity in the coming days, which could aid firefighting efforts.

The Park Fire is currently the largest active wildfire in the U.S., with thousands of firefighters from California, Utah, and Texas deployed to combat it.