Snoqualmie Tunnel via The Iron Horse Trail

For something completely different, try this restored railroad tunnel that offers a slightly unnerving 11,890ft walk under Snoqualmie Pass in near total darkness. Complete with dripping walls, echoing voices, misty air and a chilly breeze, this short trek through a piece of railroading history makes for the perfect Halloween hike.
Total Distance: 5.0 miles
Total Ascent: 0ft
Highest Point: 2500ft
Difficulty: Easy
Our Hiking Time: 2h 30m
Required Permit: Discover Pass
To get there, take I-90 to exit #54 and head right. Almost immediately take a left onto State Route 906, following the signs to Snoqualmie Tunnel. In about a half-mile, take a right just before the Highway Maintenance area. In a few hundred feet turn right into the trailhead parking lot. View Google Directions >>
From the trailhead walk the gravel path the short distance to the tunnel entrance. The wide, graveled railroad grade is flat and easy for large groups and bikers to share the trail. At the entrance note the wooden doors used to seal the tunnel between trains during the winter months. In the past these were used to minimize the ice that would form in the tunnel. For the same reason, the tunnel closes every year from November 1 to May 1, to prevent ice-related injuries. As we mentioned, the tunnel is a chilly and dark, so put on your jacket and headlamp before you plunge into the darkness.

The faint pinpoint of light ahead is the other end of the tunnel, and you’ll spend the next hour or so watching it get bigger and brighter. Once you emerge from the tunnel, be sure to linger and take in the decent views of nearby Granite Mountain, Denny Mountain, Bandera Mountain and McCellan Butte. As you turn around, take note of the second arched entrance that many say was made in preparation for a parallel tunnel that was never built. Because of the slight curve at the beginning of the tunnel, you will not have the light at the end of the tunnel to guide you for most of the way, making the return trip a little spookier.

This is a great hike for the whole family around this time of the year. There’s no elevation gain, the trail is wide enough for everyone to share, and a tunnel is a decent option on a rainy autumn day. If you’re looking to minimize the number of folks you share the trail with, we recommend you head out to the tunnel earlier in the day, as it can become crowded later. Remember to bring a strong flashlight or headlamp and enough layers to keep you warm.


Back around the turn of the last century, the Chicago, Milwaukee, St. Paul and Pacific Railroad finally connected Seattle to the rest of its eastern lines. They were a little behind their competition, as the Great Northern Railway had completed this feat over a decade earlier. Like Great Northern, the Milwaukee folks underestimated the Cascade snows and began operation without a tunnel, building the Laconia Station at Snoqualmie Pass to help keep the trains running through the winter. It only took a few years of heavy snow to convince the railroad to accelerate its plans to build a tunnel.

Early surveys began in 1908, and some initial construction preparation was started in 1911, but not until after the particularly nasty winter of 1912-13 did construction begin in earnest. In roughly 15 months, around 2,500 “tunnel stiffs” bored into the mountain from either end of the tunnel, burning through 340 tons of dynamite and removing 180,000 cubic yards of rock. They met on August 5, 1914 and the first passenger came through Tunnel 50 on January 24, 1915. In 1917 the tunnel was connected to the lines that powered the railroad's hybrid electric-steam engines in order to deal with ventilation problems, and the large wooden housing for the electrical boxes still line the tunnel today.

Times change and over the years traveling to the ski slopes by rail slowly gave way to private automobiles. The railroad declined and the last Milwaukee train passed through the tunnel on March 15, 1980. The railroad abandoned its land and the tunnel was closed. Ownership passed to Washington State, and for the next 15 years, tracks were removed and the Iron Horse State Park slowly began to take shape, but without the Snoqualmie Tunnel, the park remained divided. Then, on September 24, 1994 old Tunnel 50 was re-opened, creating an unbroken trail that now stretches 110 miles across the state. The tunnel was again closed on January 30, 2009 for renovations including adding another 4-inch layer of concrete on the walls and ceiling. It reopened July 5, 2011.
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