A Colorado Bulldog is a hybrid Bull breed dog that started in the United States of America around 1950. The Colorado Bulldog was developed from Johnson lines of American Bulldogs crossed with working AmStaffs and Pit Bull Terriers. Breeders started mixing working bulldogs with working bull terriers for rual use as flock and property guard as well as hog catching and hunting. Check out our collection of Colorado Bulldog dog names for male or female puppies.