FORT COLLINS, Colo. (AP) — Firefighters are working to contain a wildfire that began as a controlled burn and is now threatening about 50 homes in northern Colorado.

Residents were ordered to evacuate near the Elk Fire northwest of Fort Collins on Wednesday. The Larimer County Sheriff’s Office said Thursday that the fire, including the original prescribed burn, covers about 620 acres (251 hectares) and is 40 percent contained.

Dry, windy weather is keeping the fire danger high around much of Colorado.

Wildfires are still burning near Salida (suh-LY’-duh), Rifle and Ridgway.