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Ride This : Mt. St Helens – Spirit Lake Highway

A while back I came upon an organized ride called Tour De Blast, which followed Spirit Lake Highway up to an amazing view of the north side of Mt. St Helens from the Johnson Observatory. Ever since being inspired by this ride 4 or 5 years ago I have made sure to ride this at least once a year.


Mt.St Helens History

Mt. St Helens as an active volcano erupted in from the North side in 1980, killing 48 people and had a devastating effect on the scenery around this area, lava slides, moving rocks and burning down all greenery in it’s path. Combine this with twisting smooth wide roads all the way up to the national volcanic monument at Johnson Ridge make for an amazing ride.

Just up I5 from Portland is a small town called Castle Rock, Washington, being only an hour away this becomes a very accessible ride. The main road out of Castle Rock goes all the way to the mt. st helens observatory, but the early part of Spirit Lake Highway (504) is pretty mundane, little killer yet more filler, so we recommend starting a little closer.

Ride Details

This is an out and back that is very simple, and offers frequent stops for water, shown in ride with gps map, but no real food stops and has amazing views of Mt. St. Helens and Mt. Adams plus a trip to a stunning lake – Cold Water Lake.

A good start point is Toutle High School or even the one I use the most is a gravel visitor parking lot at the intersection of 504 and 505 which cuts out a few miles by being a little closer. A lot of the route has wide, clean shoulders and after many rides never had problems with cars.

This route is best done on a road bike, there is a lot of elevation, most is gradual, although the grade does kick up for the last mile to the observatory. the ride with GPD below shows 10,000ft, this is incorrect it is actually 7,300ft


  • Coldwater Lake off the road at mile 31 is definitely worth a visit, even though you have to stop on a descent. (photos below). Water and bathrooms are available.
  • In the summer it can be very exposed and hot. Pick day’s wisely and take sunscreen.
  • The ride out is 90% up, so start off slow. Coming back, there is still a good climb of 1800ft, so don’t underestimate it, thinking its all down.
  • For another wicked ride in this area check out the Windy Ridge ride that goes up the other side of St. Helens.

Our Journey in mid-May 2018


Starting the day off good with a picture.


Elkrock Viewpoint – Mile 22


Coldwater Lake – Mile 32, Pulloff is on a downhill, so headsup.sthelens_web-7sthelens_web-8sthelens_web-9sthelens_web-10

Anthony drilling up the final climb to the observatory.


Loowit Viewpoint – Milepoint 38 (almost to the top, skip it if you have momentum)


Middle of May, a little snow can be seen at 4,000ft


Group Suntan lotion re application. Pro tip, fill a contact lens case with sunscreen, cheap, leakproof, refillable and small.sthelens_web-19sthelens_web-20

The descent back down is pretty sweet, we managed to hit 46mph without even trying.

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