City of Trees Marathon Returns to Boise on October 11 with Near-Full Registration

Boise, Idaho – October 10, 2025.

The City of Trees Marathon returns to the Boise River Greenbelt this Saturday, October 11, 2025, bringing runners from across the Northwest to experience one of Idaho’s most scenic and community-driven endurance events.

The race begins and ends at Payette Brewing Co., 733 S. Pioneer Street, Boise, ID 83702, and features four distances: Marathon, Half Marathon, 10K, and 5K.

Organizers are preparing for what could be one of the most crowded editions in recent years. As of Friday morning, nearly all categories are close to capacity. The 5K is already sold out, while the other three events still have limited availability.

Registration Snapshot

Late registrants should note that anyone signing up after October 2 is not guaranteed the official race T-shirt, though all finishers will receive a medal, post-race food and drinks, and sponsor swag.

Scenic Course, Real Challenges

The marathon course winds along Boise’s famous Greenbelt system, following the river through shaded trails and open park sections. This year’s route includes minor adjustments to account for ongoing Greenbelt maintenance, including sidewalk construction and small flood-prone areas.

Organizers warn runners that the Boise River can be unpredictable in early fall, and certain sections may have temporary detours due to flooding, sinkholes, or wildlife crossings. Still, the natural setting remains one of the event’s biggest draws.

“It’s what makes this marathon so distinct – you’re surrounded by trees, hearing the river, and running in the heart of Boise,” said race director Emily Kraus. “Even with the challenges, it’s a course that connects people to the city’s environment.”

Aid stations will be available approximately every two miles, offering water, electrolyte drinks, and medical support. Marathoners will complete a second loop of the course, rejoining the half-marathon route near Pioneer Park around mile 13.

Start Times and Atmosphere

• Marathon: 8:00 a.m.
• Half Marathon: 8:30 a.m.
• 10K and 5K: 9:00 a.m.

Packet pickup is scheduled for Friday, October 10, at Payette Brewing Co., from noon to 6 p.m. Runners are encouraged to arrive early on race day, as parking near the start line is limited.

Boise’s fall weather should offer ideal running conditions – morning temperatures around 42°F (6°C), climbing to a mild 64°F (18°C) by midday, under mostly clear skies.

Participants can use the RaceJoy mobile app for live tracking, pace alerts, and interactive cheering from spectators along the route.

Swag, Awards, and Post-Race Celebration

All finishers receive an official medal, finisher food and drink, and sponsor swag, with early registrants receiving what organizers call the “comfiest long-sleeve T-shirt” in the event’s history.

After crossing the finish line, runners and their supporters can gather at Payette Brewing for refreshments and live entertainment. Food trucks and local vendors will be on-site throughout the afternoon, rounding out a community event that’s as much about celebration as it is competition.

Tradition and Spirit

Since its founding, the City of Trees Marathon has represented the best of Boise – a mix of outdoor fitness, small-town camaraderie, and respect for nature.

The course’s combination of riverfront serenity and urban energy has made it a favorite for both local runners and out-of-state visitors seeking a more personal racing experience.

For veteran runner Mark Jensen, who has completed the marathon five times, the event is more than just a race:

“It’s Boise showing off – the trees, the river, the people cheering you on. There’s no better way to see the city than on foot.”

The City of Trees Marathon begins Saturday morning, October 11, with the marathon starting promptly at 8:00 a.m. Those still hoping to join should register online before midnight. For course maps, safety updates, and parking information, visit the official event site under the “Event Info” tab.