A wildfire in northwest Colorado forced evacuations in Routt County, south of Steamboat Springs, county officials said Sunday.

Resources were on scene for the Green Ridge fire, which had burned about seven acres near Stagecoach River, with no containment as of 4 p.m.

Mandatory evacuations were ordered for an area east of Stagecoach River and south of Blacktail Mountain, officials said. Residents were advised to leave their homes immediately.

“LEAVE NOW,” a Routt County social media post ordered. “Do not delay to pack belongings.”

An area west of the evacuation zone was placed in pre-evacuation status.

The cause of the fire had not been determined as of Sunday afternoon.