The annual Tough Mudder Whistler event is held across multiple days in the scenic Callaghan Valley area of Whistler resort during the warm Summer season. It features a variety of obstacles that are sure to challenge everyone. The slopes at Tough Mudder Whistler were practically made for mud courses. Climb, then climb some more and when your thighs are burning and your lungs are calling out for mercy you keep going. Because there is only one way to cross that finish line alongside your teammates at Tough Mudder in Whistler resort.