Training at Fort Carson with rocket launchers prompted calls from residents asking the source of the noise.
Residents in Security-Widefield reported hearing multiple booms and explosions.
The noise was due to training using the M.L.R.S. multiple launch rocket system. The vehicles can fire 12 surface to surface rockets in less than a minute.
Fort Carson says National Guard Troops are training with the M.L.R.S. through the weekend.