A wildfire burning in northwest Colorado is threatening about 25 homes and prompting evacuations near Elk Springs as firefighters work to get it under control.

The Winter Valley Fire broke out Thursday night west of Craig, and is burning an estimated 5,200 acres on BLM and private land.

The fire temporarily shut down both directions of Highway 40 between Maybel and Elk Springs. The road has since reopened, but CSP asks that drivers proceed with caution as crews continue work.

Firefighters are monitoring winds out of the south and southwest that are expected to continue through Friday afternoon and evening.

Heavy smoke from the blaze can be seen from the highway.

The cause of the fire is under investigation.