Rulison, ColoradoRulison is an unincorporated community in Garfield County, Colorado, United States. Rulison is accessible from Interstate 70 and U.S. Route 6.HistoryRulison is most notable for being the namesake of the Project Rulison nuclear test on September 10, 1969. Rulison never had a post office, and is served by both the Rifle and Parachute post offices.