Tunnel Light Marathon: Pacing & Race-Day Strategy
A pitch-black tunnel start under the Cascades, then a relentless downhill rail-trail to a Boston qualifier.
- Where:
- North Bend, Washington
- When:
- September
- Course:
- Steep net downhill · rail-trail
- Best run as:
- Even pace
Course & elevation
Tunnel Light begins inside the former Snoqualmie railroad tunnel, where headlamps light a flat, two-mile descent through the dark before you burst into daylight on the Palouse-to-Cascades rail-trail. From there the crushed-gravel grade falls steadily for the entire race — well over a thousand feet of net drop — making it one of the most reliable BQ-chasing courses anywhere, provided your quads can take the pounding.
- Start → Finish
- 2,550 → 500 ft
- Net
- −2,050 ft
- Total gain
- ≈ 267 ft
Key moments
- Mile 0–2Headlamp-lit descent through the cool, dark Snoqualmie Tunnel — mind your footing on the gravel.
- Mile 3–20Steady, uninterrupted downhill on the shaded rail-trail; resist the urge to hammer and let gravity do the work.
- Mile 23–26.2The grade eases near the finish — quad fatigue bites here, so keep turnover quick and light.
Pacing strategy
Run the descent with a short, quick, low-impact stride rather than braking or over-striding — pounding the downhill early will blow your quads by mile 18. Even effort on this grade naturally banks a fast time, so stay smooth and patient.
Plan your mile splits
Enter your goal time to get a mile-by-mile pacing band for Tunnel Light Marathon. The even pace option is pre-selected to suit this course.
| Mile | Pace | Elapsed |
|---|---|---|
| 1 | 9:09/mi | 9:09 |
| 2 | 9:09/mi | 18:18 |
| 3 | 9:09/mi | 27:28 |
| 4 | 9:09/mi | 36:37 |
| 5 | 9:09/mi | 45:46 |
| 6 | 9:09/mi | 54:55 |
| 7 | 9:09/mi | 1:04:05 |
| 8 | 9:09/mi | 1:13:14 |
| 9 | 9:09/mi | 1:22:23 |
| 10 | 9:09/mi | 1:31:32 |
| 11 | 9:09/mi | 1:40:41 |
| 12 | 9:09/mi | 1:49:51 |
| 13 | 9:09/mi | 1:59:00 |
| 14 | 9:09/mi | 2:08:09 |
| 15 | 9:09/mi | 2:17:18 |
| 16 | 9:09/mi | 2:26:28 |
| 17 | 9:09/mi | 2:35:37 |
| 18 | 9:09/mi | 2:44:46 |
| 19 | 9:09/mi | 2:53:55 |
| 20 | 9:09/mi | 3:03:05 |
| 21 | 9:09/mi | 3:12:14 |
| 22 | 9:09/mi | 3:21:23 |
| 23 | 9:09/mi | 3:30:32 |
| 24 | 9:09/mi | 3:39:41 |
| 25 | 9:09/mi | 3:48:51 |
| 26 | 9:09/mi | 3:58:00 |
| 26.22 | 9:09/mi | 4:00:00 |
Fueling & hydration
Aid stations are spaced along the rural rail-trail (roughly every 2–3 miles) with water and sports drink; carry your own gels and a flask, since the remote course offers fewer stops than a city race. The cool, easy downhill rhythm makes it tempting to skip fuel — keep a disciplined gel schedule.
Weather
Mid-September in the Cascade foothills is crisp and often damp at the early start (40s–50s°F), with the tunnel noticeably cold — ideal racing temperatures once you’re moving.
Train for Tunnel Light Marathon
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