Mandatory evacuations have been ordered for residents living near a new wildfire that sparked in Larimer County on Saturday. 

The blaze, dubbed the Lewstone Fire, is burning northwest of Fort Collins, near Rist Canyon. The fire had grown to an estimated 140 acres by Saturday night, according to the Larimer County Sheriff’s Office. The cause is still unknown.  

[An evacuation map can be viewed at nocoalert.org] 

Two air tankers, two heavy helicopters, and 80 personnel were deployed to assist Saturday, and additional resources have been requested for Sunday, the sheriff’s office said. 

While low fire activity was expected Saturday night, firefighters planned to monitor the blaze overnight.

A Red Cross shelter has been opened in Laporte, Colo. for evacuees. 

The Cameron Peak Fire, also burning in Larimer County, west of Fort Collins,  has grown to more than 17,000 acres since August 13 and is 0 percent contained.  

Lewstone Fire as seen from Pine Acres Way on Saturday (Credit: Larimer County Sheriff’s Office, via Twitter)