Snoqualmie Tunnel Bike Ride

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An old concrete tunnel coming out of a forested mountain. The left side of the tunnel is covered, the right side has an open gate
The west side of the tunnel (where you come out) after 2 miles of darkness

The Snoqualmie Tunnel is an interesting and weird phenomenon to visit! I want to make sure it’s clear that riding a bike is NOT necessary to check it out. However, even though I’m not that big of a cyclist, I find biking to be the most enjoyable way to go through the tunnel. It’s just over two miles long, so it’s very, very dark and would take a long time to walk through it both ways! You could just make a quick stop at Hyak (exit 54 on I90, large parking area with restrooms) and check out the entrance, but if you want the experience of going through it, I recommend a bike. You do not need to be an experienced bike rider to do this! The tunnel is open May through October, I like the ride best in September when the fall colors are out.

Bright red fall leaves against a background of green bushes
Bring red vine maples are abundant on this ride in September

What is the Snoqualmie Tunnel?

The tunnel is just over two miles long that is part of the Palouse to Cascades rail trail, managed by the Washington State Parks. The trail provides recreation in both winter and summer! You can hike on it in summer, ski on it in winter, but biking is a good way to see more of it more quickly. This rail trail was the Chicago, Milwaukee, St Paul and Pacific Railroad which connected Chicago to the Salish Sea and operated from 1909 until 1980, when the land went to Washington State. The tunnel itself was completed in 1914 and was refurbished in 2011. The tunnel is open from sometime in May until the end of October.

How does the ride work?

There are two ways to do the ride:

Round trip from the Hyak parking lot (you need a Discover Pass to park here). The tunnel starts very quickly if you head west (to the right ) on the Palouse to Cascades Trail. You can see the tunnel entrance as you approach the trail. The tunnel itself is just over two miles long, so that would be a four mile ride round trip. You can continue riding on the other side as far as you like, keep in mind that you are going gradually downhill, which will make it UP hill on the way back. Another option would be to ride through the tunnel and back, and then ride the other way on the Palouse to Cascades Trail as far as you want (it’s fairly level for many miles in the other direction).

The other option is to go One way from Hyak downhill to the Homestead Valley Palouse to Cascades Trailhead off Exit 38 from I90. Doing it one way is logistically challenging because you’ll need at least two cars and enough bike racks. With two cars, four people and a four place bike rack on one of the cars it works perfect (or two people, two cars and a two place bike rack). The best way to do this is to drop one vehicle off on the way up. Take Exit 38 and go right. Immediately on the right is a trailhead for the Palouse to Cascades Trail. Leave the car here (make sure it also has a Discover Pass). Have the people get in the car with the bike rack and the bikes and drive up to Hyak (Exit 54). Park that vehicle here and start the ride. This makes for a 16 mile gentle downhill ride on gravel. You can’t coast, you’ll be pedaling! But it’s much easier than going uphill would be. When you get to the trailhead where you left the first car, you’ll pedal down a short spur to the parking lot. Have two drivers get in the car and go up to retrieve the other car with the bike rack and bring it down, then you can load up all the people and bikes.

What to expect in the Snoqualmie Tunnel and along the ride

The Tunnel

The tunnel is CHILLY even on a hot day (bring a warm layer to put on to ride through) and DARK. I highly recommend wearing a headlamp and bringing an additional headlamp or flashlight because it’s really really dark. Make sure your bike also has a taillight or at least a reflector (if you have front and rear lights, even better, you’ll use them!) You can’t really see the light at the far end when you start, so when you’re in the middle you are completely relying on the light source you bring. Make sure it has fresh batteries too! Also, there may be hikers in the tunnel so be extremely careful and take it slow.

Light at the end of a very dark and narrow tunnel
Approaching the end of the tunnel! Seeing the light again

The rest of the ride

Once you exit the tunnel, if you’re doing the one way option (which I highly recommend if you can make the logistics work), you’ll have about 14 miles of gently downhill gravel trail riding. The trail itself is wide and is mostly through the forest.

A gravel road, or wide trail, winds through tall green trees on a cloudy day on the Snoqualmie tunnel one way bike ride
The Palouse to Cascades trail has a gravel surface and winds through the forest

Along the way, you’ll go over a high bridge over a creek, as well as several trail crossings, stream crossings and small waterfalls.

A women wearing sunglasses and a bike helmet looks out over the edge of a bridge. The bridge is graveled with a metal railing and surrounded by evergreen trees
Looking out over a high bridge on the Palouse to Cascades Trail

You’ll even pass a couple of campsites next to a creek, in case you’d like to try out bike camping!

A picnic table in a dark and wet forest. There are trees around and an open area of dirt.
One of the campsites along the route! Makes for a great lunch or snack stop too

Before you know it, you’ll be at your car (pay attention to your miles so you don’t cruise on past it!) and relieving your off road adventure in the Snoqualmie Tunnel!

Three cyclists in the distance approaching the entrance to a tunnel on a gravel trail surrounded by green and orange trees with fall color
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Jennie Flaming
Jennie Thwing Flaming, Chief Adventure Officer: Jennie's life has been a continual quest for adventure (of the non-adrenalin inducing kind) from birth till now. Professionally, she pursues adventures in teaching, counseling and working to obliterate institutional racism for students in our region's public schools and also works as a tour and hiking guide. Previous professional adventures include working in schools in Seattle and Alaska, leading tours and managing tour guides and presenting traveling science shows and lessons with Pacific Science Center. She believes in sharing her beloved Pacific Northwest home with visitors. She likes to be outdoors and spend time with the people she loves. Jennie is born and raised in Seattle and has also lived in Alaska and the Netherlands.