Longmont Half Marathon & 5K

Thursday, July 4, 2024 • Longmont, CO • Course Map

Lying just east of the front range of the Rocky Mountains and Longs Peak, one of Colorado’s many mountains that peak above 14,000 feet, Longmont plays host to this race on the 4th of July every year, along an out-and-back course that takes runners along a trail system that winds through several of the city’s parks.

Runners first make their way through Sandstone Ranch Park, running clockwise around the park and continuing south through the park after completing a full loop. From there, the course continues on the road briefly before heading onto the St. Vrain Greenway trail, which winds alongside the St. Vrain Creek for five miles diagonally through the city and is part of the Front Range Trail, a running, walking and biking trail system that is eventually planned to stretch from Wyoming to New Mexico.

The half marathon course follows the Left Hand Creek for much of the course, parting ways with the St. Vrain Greenway Trail to follow the Left Hand Creek Trail between miles 5 and 6. By this point, runners are heading closer to downtown Longmont, while still continuing along the greenway trail until reaching Kanemoto Park.

The race route turns around here, and runners then head back in the direction they came and back into Sandstone Ranch Park, where the race finish line lies.

Race Weather & Climate

Located just east of Rocky Mountain National Park in central northern Colorado, about 40 miles north of Denver, Longmont typically sees its warmest weather of the year in July, which has brought record temperatures here as low as 40 degrees (in 1994) and as high as 106 degrees (in 1973).

Course Map

See the race route map for the Longmont Half Marathon here.

Starting Time

  • 6:00 AM – half marathon
  • 7:00 AM – 5K


  • $55 – $80 for the half marathon
  • $30 – $55 for the 5K


To reserve your spot in the mid-summer 2024 running of the Longmont Half Marathon, register online at RunSignUp.com here.

Official Race Website



Ever run in the Longmont Half Marathon? Share your impressions here, or post your review in the Comments below.