The Colossal Vail 50/50 consists of a 50 kilometer and a 50 mile race, using two out and back legs on the Arizona Trail. There is also a Kids Run and an Arizona Trail Day associated with the event.
No matter how you attempt this route, the going is strenuous and the distance is long. It's best to do some serious training before attempting this route.
To begin, all runners travel south from La Posta Quemada Ranch in Colossal Cave Mountain Park, and continue on to a bit north of Twin Tanks. The 50K finishers just return to LPQ. 50M runners stay on the Arizona Trail north to the boundary of Saguaro NP, then return to LPQ. 50M runners have the option to stop at LPQ and get credit for a 50k finish if the extra 18.5 miles sound a bit stiff.
The course is scenic and fast, albeit a bit long. Aid stations are well placed and wellstocked. The 50k is a good beginning ultra marathoner’s trail run. It traverses the high desert east of Tucson, Arizona at at time of year when sunny daytime temperatures normally reach the mid 70s. The race is held in conjunction with one of the Arizona Trail Days--an array of exhibits, talks, food, and activities, including a Kids Run for 7-12 year olds at 11:00 AM. The adult races benefit the Arizona Trail Association.
More information on the ATA’s website