Updated December 22, 2024

For trail running enthusiasts, the Colossal Vail 50/50 presents an irresistible opportunity to challenge yourself amidst the stunning desert landscapes of southern Arizona. Set for the first week of December and organized by Fleet Feet Tucson and the Arizona Trail Association, this race takes place in Colossal Cave Mountain Park, about 24 miles southeast of Tucson, and offers some of the finest high desert trail running experiences available in the Southwest. The event is a key part of the Arizona Triple 50, alongside two other iconic races, making it a bucket-list adventure for ultrarunners. Strambecco rates the Colossal Vail 50/50 as one of the Best Trail Running Race Events in the Southwest and one of the Best Trail Running Race Events in Arizona.

Whether you're gearing up for the 50-mile ultra, the 55K (34 miles), or the long half marathon, each course follows portions of the Arizona Trail, weaving through breathtaking high desert terrain, canyons, and rolling hills. With gentle terrain, an expertly designed course, and expansive views of the Santa Rita Mountains, it’s no wonder this event has been a hit since its debut in 2014. What sets the Colossal Vail 50/50 apart is its fast course, great scenery, and community-centered atmosphere, complete with well-stocked aid stations, comprehensive emergency communications, and a post-race celebration that brings runners together to share in their accomplishments.

Event Course & Info

The Colossal Vail 50/50 offers three race distances: a 50-mile, 55K, and two variations of the half marathon (day and night). Each course is designed for runners looking to experience the vast beauty of southern Arizona’s desert while tackling rolling hills and moderately technical trails. All races follow an out-and-back course format, starting and finishing at La Posta Quemada Ranch within Colossal Cave Mountain Park. The scenery transitions from desert cacti and yuccas to riparian zones as you move across different parts of the Arizona Trail, offering a varied and visually rewarding experience.

The 50-mile course is the most challenging, featuring a total elevation gain of approximately 4,000 feet as runners traverse the Arizona Trail through parts of Passages 7 & 8, passing through scenic riparian areas, open deserts, and rugged canyons. Starting from Colossal Cave Mountain Park, runners will head south, crossing Cienega Creek, navigating limestone formations, and passing under two tunnels beneath I-10 and Highway 83. The route offers sweeping views of the Santa Rita Mountains, with the high point at 4,200 feet reached after a steady climb. Aid stations are located at strategic points, including Gabe Zimmerman Trailhead at mile 4.9, Sahuarita Road at mile 11, and Peaks View at mile 16.9, with well-stocked supplies like Tailwind Nutrition, snacks, and hydration.

The 55K course, measuring approximately 34 miles, shares much of the same route as the 50-mile course but has a slightly lower total elevation gain of around 3,000 feet. Like the 50-mile, this course takes runners through dramatic desert landscapes and under the I-10 tunnel, offering expansive views and varied terrain. Runners will encounter many of the same aid stations, ensuring support throughout their run. The course is designed to be fast, making it a great option for runners looking to push their endurance limits on a relatively runnable trail with fewer technical sections.

For runners who prefer shorter distances, the half-marathon options offer two distinct experiences: a 13.6-mile daytime-half marathon and a 13.1-mile nighttime version. Both courses begin and end at La Posta Quemada Ranch, taking participants on a fast out-and-back route along the Arizona Trail. The terrain is relatively flat, making these races accessible yet still challenging, with stunning desert vistas along the way. Runners can enjoy the open trails under the desert sun or, in the night version, the cool evening air and starlit sky. Aid stations for the half marathon provide the necessary hydration and nutrition for a solid performance, and both variations promise an exciting and unique desert running experience.

The Colossal Vail 50/50 has a field limit of 300 participants across all distances, and spots fill up quickly so early registration is highly recommended. The 50-mile and 55K races both begin at 6:30 AM, while the half marathon starts at 8:00 AM. Additionally, the nighttime half marathon offers a unique experience by starting at 6:00 PM, allowing runners to enjoy the desert landscape under the stars. The event is well-supported by aid stations approximately every 4-6 miles, stocked with essentials such as chips, pretzels, cookies, boiled potatoes, peanut butter and jelly sandwiches, and Tailwind Nutrition to fuel participants throughout the race. Completion cutoff times are generous, with the 50-mile race allowing 14 hours, the 55K allowing 11 hours, and the half marathon offering plenty of time for participants to finish. At the end of the race, runners are invited to a post-race celebration at La Posta Quemada Ranch, where they can enjoy food, drinks, and camaraderie. Awards are given to top finishers in each distance, and all participants receive high-quality event swag, making the event a true celebration of endurance and community.

Related Events

Multi-sport athletes looking for other premier races and events in Arizona and the broader Southwest region can take a peek at all of our related Strambecco Best rated event guides:

• Best Gravel Cycling Race Events in the Southwest
• Best Road Cycling Race Events in the Southwest
• Best MTB Race Events in the Southwest
• Best Trail Running Race Events in the Southwest
• Best Cycling Race Events in Arizona

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