Sugar Colt (1966)

Near the end of the American Civil War, an entire unit of one hundred Union sharpshooters vanish into thin air in a rugged, mountainous region. To shed light on their mysterious disappearance, Sugar Colt, a former special agent, superb marksman, and director of a shooting academy, rides into the dusty town of Snake Valley, posing as Doctor Tom Cooper. But, newcomers, especially the brazen ones, are rarely treated with respect in the God-forsaken hamlet. Now, Tom will have to put his skills to good use, as guns have the final say. Will Sugar Colt get to the bottom of what happened to the missing U.S. Cavalry officers?