The Larimer County Sheriff's Office reports that a fire has grown to about 25 acres near Indian Mountain, roughly 4 miles north of Lyons.
"Multiple fire resources," are on scene, according to the sheriff's office. Authorities are using the hashtag #DakotaRidgeFire2016 to track the fire.
Officials with local sheriff's offices have described it as a wildfire and a grass fire.
The fire is near 22000 Dakota Ridge Road, according to the Boulder County Sheriff's Office.