The Federal Aviation Administration has launched an investigation in northeastern Colorado and southwest Nebraska.
For the past two weeks, clusters of unidentified drones have been flying over rural areas at night.
Multiple FAA divisions and government agencies are investigating these reports.
Ian Gregor FAA spokesman The drones have blinking lights, and are flying in square grid patterns nearly every night between 5 and 10 p.m.
According to Reuters, they appear to be widening their path.