HALF DISTANCE TRIATHLON DES MOINES IOWA Swim Course (1.9 KM): The point-to-point swim starts at Gray's Lake Peninsula. Spectators can watch from Gray's Lake Bridge. The swim ends near the Transition area in Gray's Lake Park. Average water temperature is 72°F (22°C). Bike Course (56 miles): Athletes ride from downtown Des Moines to West Des Moines and back. The route features rolling hills, smooth new roads, and closed traffic, ensuring a fast and safe ride. Run Course (13.1 miles): This ...