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Boulder River Trail

  4.3 ( 13 ) Favorite


8.3 mile 13.4 kilometer out and back
95% Runnable


Ascent: 773' 236 m
Descent: -773' -236 m
High: 1,567' 478 m
Low: 1,044' 318 m


Avg Grade: 4% (2°)
Max Grade: 13% (8°)


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Trail shared by Justin S.

An earthy trail that is abundant in rivers, waterfalls, and beautiful flora/fauna.

Justin S.

Features Birding · Fall Colors · River/Creek · Views · Waterfall · Wildflowers · Wildlife


Boulder River Trail is a 8.4 mile out and back trail located near Arlington, Washington that features a waterfall and beautiful flora/fauna. The terrain found on this route include dry wide/narrow paths, mud, river rock, and bridges. Giant moss-covered trees make great shade from the sun or rain. Twin waterfalls near the beginning of the run will encourage you to explore as you continue on.

Need to Know

The trail is primarily used for hiking, trail running & walking and is accessible year-round.

Runner Notes

This trail is fairly easy on the legs, perfect for running or jogging.


The trail starts on a nice open path which was once an old railroad logging grade. As you get closer to the river, you can hear the rush of Boulder Falls. The bank is steep and there almost no access directly. After passing a nice camp spot, there will be a break in the trees, and the river can finally be seen.

Continue on a bit and you'll discover the twin waterfall! There is dripping moss and bright yellow monkey flowers between the waterfalls. If you keep going you'll come to a short switchback. As you make your first switch on the left-hand side is a huge old-growth tree made for photo ops. There is more old-growth along the trail, saved by the wilderness boundary. Another waterfall is further up the trail for a perfect picture. After the second big waterfall, the trail climbs away from the river. Although there are no mountain views, the forest here is still amazing.

Flora & Fauna

There is dripping moss and bright yellow monkey flowers between the waterfalls. Wide variety of trees and shrubbery throughout the trail (Sword fern, soft maidenhair fern, deer fern, moss and twin flower)

History & Background

The USGS have the falls marked on the map, yet the trail doesn't provide a view of the falls, so when runners arrive at nearby Feature Show Falls, they assume they are looking at Boulder Falls. The river is hidden from view by the thick forest, which clearly explains why so few have found the actual falls. Those who do find it will discover the true unnamed waterfall.

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Jun 3, 2018
Aishwarya Nair
Mar 29, 2016
ccszynal Szynal
Done on a pleasantly drizzly day. There are a few landslides but all are easily navigated. All in all a beautifully maintained trail through old gr... 7.1mi
Feb 24, 2016
ccszynal Szynal
Aug 26, 2015
Brandy Parker
Amazing waterfall views 4.4mi

Trail Ratings

  4.3 from 13 votes


  4.3 from 13 votes
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Featured Run Rankings


in Washington


71 Views Last Month
4,361 Since Apr 23, 2015



Apr 23, 2015 near Darrington, WA
Apr 23, 2015 near Darrington, WA
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