Metro area firefighters are battling a wildfire in Waterton Canyon.

West Metro Fire Rescue described the fire as “small” and no structures are threatened. South Metro Fire Rescue and other local fire agencies are also working on the fire, West Metro said in a 5:08 p.m. Saturday tweet. There are no evacuation notices.

Waterton Canyon, in Jefferson County, is popular with hikers, bicyclist, runners and other outdoor recreationists. Running about 6 miles from the canyon mouth up to Strontia Springs Dam, the South Platte River runs through the canyon and variety of wildlife abounds, including big horn sheep, deer, black bear and mountain lions.

The cause of the fire is under investigation.