While radar is a generally reliable method to detect and display moisture-bearing clouds, it is not foolproof and can generate false returns or "ghost" images under certain conditions.
These conditions occur sporadically around the country when the radar is being reflected off some large geographic feature like a mountain or can even be caused by man-made structures and equipment such as a wind farm. In mountainous terrain such as found in the state of Colorado such issues are more likely to occur, and unfortunately this is a physical location problem that cannot be fixed.