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DENVER — The Colorado Division of Fire Prevention and Control confirmed the agency was involved in a joint operation Monday night to investigate the source of “mystery drones” flying in northeastern Colorado.

“The joint operation found no verification of suspicious drones,” said Caley Fisher, a spokesperson for the department.

Fisher would not confirm whether the state agency used a state-owned Multi-Mission Aircraft, which is frequently used to assist in wildfire detection and providing “near real time” information about the fire to ground crews.

However, the FOX31 Problem Solvers have learned one of the state’s planes was flying last night in the area where drones had been reported.

“(The Colorado Department of Public Safety) consistently utilizes the expertise and resources of our divisions in efforts to assist our local and federal partners with ongoing investigations,” said Fisher.

The state’s Multi-Mission Aircraft includes two Pilatus PC-12 airplanes, according to the Division of Fire Prevention and Control’s website. Each is equipped with infrared and color sensors. According to the flight-plan tracking website,, one of the state planes was flying in circles northeastern Colorado for nearly five hours Monday night.

Fisher would not disclose what the plane was doing in that area.

“We do not discuss the investigative techniques or technology we’re using,” Fisher said. “We are actively monitoring reports of suspicious activity and will take action based on the level of activity and information being gathered by the (Colorado Information Analysis Center, a division of the state’s Department of Public Safety).”

“They were conducting as wide a search as possible for something. Now, whether it was for these drones or not remains to be seen,” said Steve Cowell, an aviation expert. “We do know that these planes were up there flying certain patterns over the northeastern portion of the state.

Cowell said the plane’s infrared technology can help notice heat signatures from thousands of feet in the distance, but a drone might not give off a heat signal.

“You’re not going to find a heat signature on a small drone. You may not find one on a large drone,” he said. “They’re electric motors. They’re not gas-powered engines generating a heat signature, so they’re going to be very difficult to find.”

According to the state’s description of its Multi-Mission Aircraft, each is equipped with a color sensor. Cowell said that might help detect a drone’s lights.

“It’s highly possible they may be looking for those red and green lights that are associated with these drones,” he said.