two large craft that released a dozen smaller craft which dissapered as the larger craft kept flyingAt approx. 20:05 MDT my coworker and I saw a group of objects in the eastern sky. It was late afternoon before sunset. The objects were two large craft and a group of smaller craft that were flying to the north east. The smaller craft were randomly dispersed around the two larger craft, and as the group of craft kept moving to the north east the smaller craft disappeared. The smaller craft did not crash, nor was there any light emitted from them. The two craft stayed at altitude as they moved through the sky and my co worker and I lost sight of them due to distance. The craft did not leave an exhaust trail I estimate that the craft were traveling near the speed of sound, and below the flight ceiling of commercial aircraft. This is due to the fact that a commercial flight flew overhead at 20:18 MDT and did leave an exhaust trail.From my position the craft were approximately 5 to 7 degrees above the horizon and within 5 miles of my position. The craft stayed in sight for 5 minutes and disappeared due to distance.((NUFORC Note: We spoke via telephone with the witness, and he sounded to us to be quite sober minded. PD))