2026 Southwest Series - Day 4 (AZ)

Embark on an unforgettable trail running adventure at the 2026 Southwest Series - Day 4 (AZ), held on November 11th in the stunning landscape of Flagstaff, Arizona. This popular event, part of the renowned Mainly Marathons series, offers both a 10K and 5K, catering to runners seeking a scenic and supportive race experience. Known for its "no runner left behind" policy, the Southwest Series welcomes walkers and ensures every participant crosses the finish line at their own pace.

The race unfolds within the picturesque 215-acre expanse of Buffalo Park, with the start and finish lines located at 2400 N Gemini Road. Runners will navigate a largely crushed gravel path that boasts "fast and flat" sections, all while being treated to breathtaking mountainous views and the possibility of spotting local wildlife amidst lush greenery. This multi-loop course design provides a unique and engaging experience, making it ideal for those who enjoy consistent, well-supported circuits. Typical race day conditions in November offer crisp highs around 60F and lows near 38F, with a minimal 15% chance of precipitation, providing excellent running weather.

What truly sets the Southwest Series apart is its legendary aid station, affectionately known as the "Loony Lunchbox." This "giant" and well-stocked station goes far beyond the basics, offering everything from fruit and jelly beans to sandwiches, hot coffee, water, and Gatorade, ensuring runners are well-fueled throughout their race. As a cornerstone of one of the largest race organizers in the US, Mainly Marathons, this event delivers a memorable atmosphere, drawing runners to experience one of the "World's BEST multi-day, multi-state running series".