Driving north on I-25 towards Fort Collins, Colorado I noticed a triangular flash in the sky that lasted about 3 seconds, then flashed again about every 5 seconds. As I got closer, I noticed that there were about 10 wedge shaped objects, white in color with black tips. The flashing I saw was the sun bouncing off the objects as they banked left and right, IN SYNC WITH EACH OTHER! I was close enough to confirm that these were not birds - they were much to large to be birds. I estimate each object to have a wing span of about 10 feet. They were flying in a wedge formation and banking left and right. They appeared to have forward facing wings. What caught my eye was the in sync nature of their flight path - they all banked at the exact same time. I lost sight of the objects as I drove north on the freeway. The objects were flying out of the northwest and flying towards the southeast. I also noticed a single engine prop aircraft flying in a circle just prior to seeing the objects. The aircraft was flying around the objects, basically keeping them in the center of the circle. I can provide a sketch if you would like. In addition, these are the same objects shown in a video filmed in 2013. Can provide a link if requested.