Emergency crews respond to wildfire in northern Larimer County; evacuations ordered

Multiple agencies are responding to the Pearl Fire, which broke out Monday in northern Larimer County near Crystal Lakes, the sheriff's office said.

The fire was estimated to be 138 acres in size and was not even contained as of 3:50 p.m. The sheriff's office said 50 people were working to fight the fire and more were on the way.

Air resources, including three helicopters and three firefighting aircraft, were on scene and evacuations were ordered. As of 6:30 p.m., an evacuation center was opened for the displaced at Cache La Poudre Middle School.

The mandatory and voluntary evacuations are taking place near Crystal Lakes, north of Black Mountain on the Wyoming state border.

The cause of the fire has not yet been announced.

This is a developing story that will be updated.