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Boulder Rez Marathon

Name: Boulder Rez Marathon
Start: 2026-08-15
End: 2026-08-15
Location: Boulder

Boulder, United States • 15 Aug 2026

Boulder Rez Marathon 2026

The event takes place at Boulder Reservoir in Boulder, Colorado (80301). The running course follows the reservoir shoreline and is routed mostly on dirt roads and trails. The route is relatively flat, with about 200 feet of total elevation gain, and offers views of the Boulder Reservoir and the Rocky Mountains.

Distances and entry types offered at the event include:

10K Run
Half Marathon
3/4 Marathon
Marathon
Marathon Relay (captain and member entries)

The event program includes packet pick up and registration, awards presentations, and a course closure later in the day. The race is organized by BBSC Endurance Sports. Pricing and availability vary by distance and entry type. Visit the organization's website for the most recent information.

United States Colorado Boulder

Race information

Website Registration

Marathon

Marathon Relay

Marathon

32 km

3/4 Marathon

Half Marathon

10 km

10k

Visit the organization's website for the most recent information.

Trail runs nearby

Saturday Jul 4

Rendezvous Run for Independence

Winter Park

5 km

A 5K run/walk in Winter Park, Colorado following the Fraser River Trail from Gondola Plaza to the Rendezvous Event Center, with an after party featuring refreshments, awards and prize giveaways.

Sunday Jul 5

Walk, Run or Bike - Golden

Golden

5 mi

10 mi

Community outdoor event in Golden offering a 12 mile bike ride, a 5 mile hike, and a 10 mile run at South Table Mountain. Participants must sign a Latinos Outdoors waiver and bring appropriate gear.

Saturday Jul 18

Thumbs Up Summer Slam

Estes Park

2 km

Repeating 2 km out and back laps on the Thumb Open Space trail in Estes Park. Participants collect a poker chip at each turnaround and the most chips wins during a sunup to sundown timeframe; 35 spots and a $100 entry fee.

Saturday Jul 18

Ranch Camp Roundup Trail Run

Glendale

5 km

10 km

A community trail event at JCC Ranch Camp on Saturday July 18 offering 5k and 10k trail options, sliding scale entry, on course water and clinic support, plus post-race tie dye and craft activities for finishers.