On Saturday, Sept. 19, the town of Frisco will host the 50th annual Run the Rockies road races. Two races — a 10k course and a half marathon-length course — will start at Copper Mountain and end on Main Street in Frisco. The 10k course is completely downhill and begins at 8:30 a.m., while the half marathon is 75% downhill and begins at 8 a.m. All runners have a cutoff time of 11:30 a.m., and the event will be followed by a post-race party at th…