Snoqualmie Tunnel – "The Seals" loop from Hyak

If you're seeking a touring cycling adventure that's truly out of the ordinary, the Snoqualmie Tunnel – "The Seals" loop from Hyak is a moderate 23.6-mile (38.0 km) route with 618 feet (188 metres) of elevation gain, typically completed in about 3 hours and 35 minutes. This popular trail offers an unforgettable journey through a historic railway tunnel, perfect for cyclists looking for a unique experience and a break from typical road rides.

What to expect on Snoqualmie Tunnel – "The Seals" loop from Hyak

The route offers a striking contrast, starting with gravel paths that lead you into the heart of the Cascade Mountains. The highlight is undoubtedly the 2.3-mile long Snoqualmie Tunnel, a dark, cold, and atmospheric passage where water drips from the ceiling and echoes fill the space. Emerging from the western end, you're greeted with expansive views down the I-90 valley and dense forests. While the former rail line ensures a gentle, consistent grade, the gravel surface outside the tunnel can be soft, making it a moderate challenge that's best suited for cyclists with tires of at least 28mm.

Planning your visit

The Snoqualmie Tunnel is typically open from May 1 to November 1, closing during winter due to hazardous ice formations, so plan your visit accordingly. Even on warm days, the tunnel maintains a consistent 50°F (10°C), so bring warm layers and powerful, reliable lights with backups for the pitch-black interior. This traffic-free route is part of the Palouse to Cascades State Park Trail, offering a preserved piece of railway history for your enjoyment.

Trail details

• Distance: 23.6 miles (38.0 km)
• Elevation gain: 618 feet (188 metres)
• Difficulty: moderate
• Estimated time: 3 hours and 35 minutes