Fleet Feet Madison keeps a pretty nice running, duathlon, and triathlon calendar - http://www.fleetfeetmadison.com/calendar
Ironman Wisconsin in Madison is one of the tougher Ironman courses in North America. The swim is two loops in Lake Monona in downtown Madison, in front of Monona Terrace. The bike makes two loops west of Madison through some pretty hilly sections. The run is two loops and includes the bike path along the lake and a loop of the University of Wisconsin Camp Randall Stadium.
