The Colossal Vail 50/50 is an adventurous ultra run on portions of the Arizona Trail near the community of Vail (24 miles southeast of Tucson). Starting and finishing at Colossal Cave Mountain Park, both the 50K and 50-mile courses feature some of the greatest high desert trail running opportunities in this part of the state. Please note that both routes are long. At this point our best estimate of the actual distance of the "50K" is about 33.9 miles. The "50-mile" is about 52.4 miles. We probably won't change the event name to protect the innocents who attempt this run.