The cause of the wildfire burning south of Twin Lakes, Colorado sparked on Tuesday was from an abandoned campfire, fire officials said Wednesday evening.

The wildfire has now burned 443 acres and is zero percent contained.

Those who are in the area of the fire have been asked to evacuate, in particular near Interlaken and County Road 25, the Lake County Sheriff’s Office said.

“It was determined that the fire originated from an abandoned campfire located about 60 yards from the Interlaken trail and 1.5 miles from the trailhead,” the sheriff’s office said on a Facebook post. “This campfire was not properly extinguished and continued to burn. It is believed that the campfire was abandoned several days prior to its report on June 11.”

Currently officials have no leads on who left the fire unattended and the sheriff’s office and US Forest Service will be utilizing a tip line and other information platforms to identify potential suspects.

The sheriff’s office is asking if anybody has information regarding campers that had a fire near the Interlaken resort between June 7-11 to please call the Tip Line at 303-275-5266.

Approximately 135 personnel are fighting the fire, supported by four helicopters and a fixed-wing air tanker, dropping water and fire retardant around the fire.

Crews on the ground are working to protect not only private property, but Interlaken Historic District buildings, Canada lynx habitat and utility infrastructure as well.

The sheriff’s office said Interlaken Historic District buildings are not currently threatened.