Started in North Platte, NE after forecasting. My morning target was Brush, CO. (I like to pinpoint just for the fun of it). Heading west, we watched the storms developing and putting down hail in Denver. Eight miles west of Last Chance, CO, the storm organized into a beautifully photogenic supercell. This storm produced a number of funnels. Nearing sunset, we headed north and after emerged from the rain to be treated to several rainbows, including a double rainbow. Then, just a few minutes before the sun set, the collapsing storm produced a jaw dropping mammatus display.