The inaugural Great Western Trail Race is happening Saturday. According to the Greeley Tribune, the event will feature 5K, 10K and half-marathon official race courses The first race will begin at 8 a.m. Same-day registration may be available on site, but online registration is preferred at runsignup.com/Race/CO/Windsor/GreatWesternTrailRace. A post-race festival will be hosted at Severance Community Park, 100 Waterfowl Way.