Tough Mudder is a 10-12 mile (18-20 km) obstacle course designed to test all-around strength, stamina, teamwork, and mental grit. Tough Mudder is probably the toughest event on the planet. Run Tough Mudder for as little as $20 or Tough Mudder Half for as little as $10. Change lives and help others conquer their challenges and fears. Volunteer and be at the heart of the mud covered action at one of the largest mud obstacle events near you. Free Tough Mudder Volunteer T-shirt and beer!