Overview Tough Mudder is an obstacle course series with no clock and no winners: teams and strangers haul each other over walls and through a 34-degree ice pit to earn an orange headband at the finish. Courses come in a 5K with 12-plus obstacles and a 15K with 20-plus, and the Infinity format gives people eight hours to run both as many times as they can. The endurance events go longer: 12 hours at America's Toughest Mudder and 24 hours on a five-mile lap at World's Toughest Mudder. Spartan acquired Tough Mudder in 2020, and runs it alongside Spartan races and DEKA. On site Events take over farms, ranches and raceways, from Reveille Peak Ranch in Texas to Lake Elsinore Raceway in California and Fort Carson in Colorado. The obstacles are the show: Block Ness Monster makes a team rotate 500-pound blocks, Mudderhorn goes forty feet up a net and forty down, Cage Crawl leaves four inches of air above a 48-foot water pit, Cry Baby is a crawl through tear gas, and Everest is a greased 13-foot quarterpipe where runners reach for a hand from whoever made it up first. Runners start and finish under an arch, and a festival area has a main stage. Audience Most people sign up as teams, and the series counts corporate teams and the military among its core community. The headband color counts finishes: orange for a first, green for a second, blue for a third, with rarer shades after that, and the series keeps a public roll of people who have finished 100. In 2025, 38% of participants were returning Mudders, per the series' 2026 deck. Military and first responders get a standing 25% discount. Track record Will Dean and Guy Livingstone co-founded Tough Mudder in 2010 and held the first event on May 2, 2010, at Bear Creek Mountain Resort near Allentown, Pennsylvania. World's Toughest Mudder started in 2011, and by 2016 more than three million people had taken part in Tough Mudder events worldwide. Spartan bought the company in February 2020 out of bankruptcy proceedings. In Tough Mudder's own survey, 70% of participants said they were likely to buy from partners who activate on site. Brand presence National partners' logos run on the start and finish arches and the main-stage step-and-repeat at every U.S. event. The 2026 partnership deck adds finish-line sampling, branded on-course hydration stations, a 10-by-10 footprint in the festival area, and a place in the pre- and post-event emails sent to every participant of each U.S. event. Givestar is the official fundraising platform, where Mudders raise money for up to four charities at once, and GovX verifies the military discount.