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The Tunnel Light Marathon is a fast, USATF-certified Boston Qualifier featuring a unique 2.4-mile segment through a dark mountain tunnel and a scenic downhill finish.
Course Highlights
The Tunnel Light Marathon offers a unique and breathtaking course that takes runners through the heart of the Cascade Mountains. The undisputed highlight of the race is the Snoqualmie Tunnel, a 2.4-mile stretch of absolute darkness that begins shortly after the halfway point. Runners are required to carry a headlamp or light source to navigate this cool, damp, and historic passage through the mountain. Exiting the tunnel reveals stunning vistas of the surrounding peaks and lush forests. For the 2026 season, the course has been modified to include a scenic out-and-back segment heading east from the start at Hyak Sno-Park before participants return to the halfway mark and enter the tunnel. The entire route is set on a well-maintained rail-trail, offering a serene atmosphere away from vehicle traffic, surrounded by the natural beauty of Washington state.
Race Details
The 2026 Tunnel Light Marathon is scheduled for September 13, 2026, starting at the Hyak Sno-Park Trailhead at Snoqualmie Pass. The race begins at 08:00, with an early start option available at 07:00 for those anticipating a finish over five hours. Due to storm damage on portions of the original route, the 2026 event features an alternate course that maintains the race’s reputation for speed. The point-to-point course is primarily composed of packed gravel on a historic railway grade, providing a soft but stable surface that is gentle on the joints while still being fast enough for high performance. With a net elevation drop of approximately 1,000 feet, the course is a USATF-certified Boston Qualifier. Runners will find nine fully staffed aid stations spaced roughly every 2.5 miles, providing water, Tailwind electrolyte drink, and Honey Stinger gels at select locations.
Why Runners Love It
Runners flock to the Tunnel Light Marathon for its reputation as one of the fastest marathon courses in the United States. The consistent downhill grade and the low starting elevation create the perfect conditions for setting a personal record or securing a coveted Boston Marathon qualifying time. Beyond the performance benefits, participants appreciate the intimate and well-organized nature of the event. The unique experience of running through the mountain tunnel provides a memorable challenge that distinguishes this race from typical road marathons. The camaraderie among runners in the darkness of the tunnel, followed by the rewarding descent through scenic mountain landscapes, makes for an unforgettable race day. Additionally, the event is praised for its professional organization, including reliable shuttle services and enthusiastic volunteer support, ensuring a seamless experience from start to finish.
Ready to chase your next personal best in the mountains? Secure your spot on the starting line and prepare for the light at the end of the tunnel by registering on the official Tunnel Marathons website.
At a Glance
- Location: Snoqualmie Pass, WA — United States
- Next Date: 2026-09-13
- Distances: [‘Marathon’, ‘Half Marathon’]
- Start Time: 08:00
Register & Learn More
Visit the official race website for entry details, course maps, and registration: https://www.tunnelmarathon.com
The Tunnel Light Marathon is a fast, USATF-certified Boston Qualifier featuring a unique 2.4-mile segment through a dark mountain tunnel and a scenic downhill finish.
Course Highlights
The Tunnel Light Marathon offers a unique and breathtaking course that takes runners through the heart of the Cascade Mountains. The undisputed highlight of the race is the Snoqualmie Tunnel, a 2.4-mile stretch of absolute darkness that begins shortly after the halfway point. Runners are required to carry a headlamp or light source to navigate this cool, damp, and historic passage through the mountain. Exiting the tunnel reveals stunning vistas of the surrounding peaks and lush forests. For the 2026 season, the course has been modified to include a scenic out-and-back segment heading east from the start at Hyak Sno-Park before participants return to the halfway mark and enter the tunnel. The entire route is set on a well-maintained rail-trail, offering a serene atmosphere away from vehicle traffic, surrounded by the natural beauty of Washington state.
Race Details
The 2026 Tunnel Light Marathon is scheduled for September 13, 2026, starting at the Hyak Sno-Park Trailhead at Snoqualmie Pass. The race begins at 08:00, with an early start option available at 07:00 for those anticipating a finish over five hours. Due to storm damage on portions of the original route, the 2026 event features an alternate course that maintains the race’s reputation for speed. The point-to-point course is primarily composed of packed gravel on a historic railway grade, providing a soft but stable surface that is gentle on the joints while still being fast enough for high performance. With a net elevation drop of approximately 1,000 feet, the course is a USATF-certified Boston Qualifier. Runners will find nine fully staffed aid stations spaced roughly every 2.5 miles, providing water, Tailwind electrolyte drink, and Honey Stinger gels at select locations.
Why Runners Love It
Runners flock to the Tunnel Light Marathon for its reputation as one of the fastest marathon courses in the United States. The consistent downhill grade and the low starting elevation create the perfect conditions for setting a personal record or securing a coveted Boston Marathon qualifying time. Beyond the performance benefits, participants appreciate the intimate and well-organized nature of the event. The unique experience of running through the mountain tunnel provides a memorable challenge that distinguishes this race from typical road marathons. The camaraderie among runners in the darkness of the tunnel, followed by the rewarding descent through scenic mountain landscapes, makes for an unforgettable race day. Additionally, the event is praised for its professional organization, including reliable shuttle services and enthusiastic volunteer support, ensuring a seamless experience from start to finish.
Ready to chase your next personal best in the mountains? Secure your spot on the starting line and prepare for the light at the end of the tunnel by registering on the official Tunnel Marathons website.
At a Glance
- Location: Snoqualmie Pass, WA — United States
- Next Date: 2026-09-13
- Distances: [‘Marathon’, ‘Half Marathon’]
- Start Time: 08:00
Register & Learn More
Visit the official race website for entry details, course maps, and registration: https://www.tunnelmarathon.com