Attention Boulder residents and travelers, mark your calendars for a day of athletic festivity and road closures. Boulderthon is set to take over the streets on Sunday, Sept. 28, with a plethora of races, including a marathon, half-marathon, 10K, and 5K. These events promise to draw a crowd, likely leading to travel delays throughout Boulder County and the city.
Those planning to move around the area on race day should take note of the suggested detours. Although everyone living on or near the race routes will maintain access to their homes, it's advised that, if possible, they steer clear of attempting to cross the course. The Boulderthon website contains detailed course maps and information on community and traffic impacts for better navigation.
From 7 a.m. to 4 p.m. on race day, various roads and trails will be affected, as posted by Boulder County. Significant closures include eastbound access from Boulder to Gunbarrel, Niwot, and Longmont on SH-119/Diagonal Highway, and multiple county roads such as Jay Rd, N 51st St, and Monarch Rd. City closures within Boulder will impact streets like Pearl St./Pearl Pkwy., Spruce St., and 14th St.
