The Daily Camera reported Thursday the Colorado Wildlife Commission approved the "Rodenator" in 2006. It explodes burrows by igniting a propane mixture pumped into the holes.
Nearby residents in Boulder have complained the method is cruel, inhumane and extremely loud. Some have reported seeing prairie dogs on fire.
Boulder County sheriff's officials have estimated the explosions exceed the county's sound limit of 50 to 55 decibels.
Employees at a ranch where the device is being used say it isn't meant to kill the animals.
It's illegal to use Rodenator in Boulder, but not in the county, where the ranch is located.