2025
I ran Boulderthon in 2025 before starting Race Across, so I don’t have a full guide for that year. Future updates may include notes and photos from that race.
2026
Quick Take
After running Boulderthon in 2025, it quickly earned a spot on my repeat bucket list. This year, I’ll be returning for the half marathon — and this time my family is coming along too.
One of the biggest reasons I chose Boulderthon is the combination of a well-organized race, mountain scenery, and the opportunity to spend a week exploring Colorado before race weekend.
This planning guide will evolve throughout my trip — from booking and training to race weekend — and I’ll update it with everything I learn along the way.
My Trip Costs
These are my expected trip costs for September 2026.
| Item | Cost |
|---|---|
| ✈️ Flight (DCA → DEN) | $250 RT/person |
| 🏠 Airbnb (Golden) | ~$700–1,200 total |
| 🚗 Rental Car | TBD |
| 🏃 Half Marathon Registration | $130 |
Registration
I registered for the half marathon on October 15, 2025 for $130.
As of July 2026, registration is already over $175, so registering early can save a significant amount. Boulderthon has become one of Colorado’s most popular races, attracting roughly 10,000 runners, so I wouldn’t wait until the last minute if you’re planning to run.
Flights
Flight: DCA ↔ DEN • Frontier • Nonstop • Carry-on included
I booked flights in late July for travel from September 19–28.
After comparing Frontier, United, and American, Frontier offered the best value by a wide margin. We booked nonstop flights from Washington National (DCA) to Denver (DEN) for $250 round trip per person, including a carry-on, using Discount Den.
Because we booked 3 tickets, the $110 Discount Den membership essentially paid for itself.
Booking Tip: We booked about two months before race weekend and paid $250 round trip nonstop from DCA. Prices were already climbing quickly, so earlier booking appears worthwhile.
Where I’m Staying
We’re planning to stay in Golden instead of Boulder.
Golden offers easy access to Boulder, the foothills, and Rocky Mountain National Park while typically providing better lodging value than staying directly in Boulder.
I’ll update this section after the trip with my thoughts on whether I’d stay there again.
Questions I’m Still Researching
- Parking strategy for race morning
- Best shakeout run in Boulder
- Packet pickup experience
- Best pre-race pasta dinner
- Whether altitude noticeably affects race-day pacing
Was this guide helpful?
I’m running a half marathon in every state and improving these guides after every race. If something was missing, outdated, or inaccurate, I’d love to hear from you.
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