HALF DISTANCE TRIATHLON DES MOINES IOWA Swim Course (1.9 KM): Experience the ultimate point-to-point swim at Gray's Lake Peninsula. Spectators enjoy panoramic views from Gray's Lake Bridge. Finish your swim just steps from Transition in Gray's Lake Park. Enjoy an average water temperature of 72°F (22°C) for an optimal swim experience. Bike Course (56 miles): Ride through the stunning countryside from downtown Des Moines to West Des Moines. This scenic course features rolling hills, new smooth ...