Bolder Boulder. Memorial Day brings the annual 10-kilometer Bolder Boulder, when more than 50,000 runners, including top international competitors, run in the country's largest race. About 100,000 spectators line the route and fill CU's Folsom Stadium to cheer on the participants. Along the racecourse rock bands, jazz musicians, African drumming groups, Elvis impersonators, belly dancers, and classical quartets spur on the runners. The race ends in Folsom Stadium for a ceremony that includes a flyover by U.S. Air Force fighter jets and skydivers who parachute onto the stadium field. Boulder, CO. 303/444–7223. www.bolderboulder.com.