In October 2006, I was training for the Seattle Half-Marathon, so I decided to go on a long run . But when I woke up Saturday morning and saw that it wasn't raining yet, I wanted to climb. So, I decided to do both! The approach to the west ridge of the North Twin Sister is 6+ miles of logging roads one way (most people bring a bike, I brought running shoes), and along with the climb, this was a great training day! A 13 mile run punctuated by a couple of thousand feet of Class 3/4 scrambling to keep it interesting. Time: 2.5 hours from car to summit, 2.25 hours from summit to car
My brief laptop mountaineering of the North Twin indicated that several climbers have had trouble staying on the correct logging roads on the approach. So in the below trip report I have included some detailed directions (read if you want). I have also included some of my photos from the climb. Enjoy!
I have attached a map (Beckey's guide, pg 40) below that shows some of the roads, as well as the trail network. Basically, you need to get on Mosquito Lake Road, either from Acme or Welcome, WA. Just north of where Mosquito Lake road crosses the Middle Fork of the Nooksack River (about 6 miles from Welcome, 10 miles from Acme), a well-graded dirt road (Road 38) branches off to the west. Take this road. At about 4.5 miles you will come to a bridge over Clearwater Creek. Shortly after this, take the right fork down to the river (Road 38 forks left). There is a gate just before the bridge over the river. This gate is usually closed, so park here and begin the hike (or bike) up the logging roads.
Click on the map for a bigger view. I have outlined the route from the gate to the summit, and added some notes to help with route finding.
The Trail/Road network
Note #1: Unless you prefer hiking or you plan to run the logging roads, I would suggest bringing a bike to ride down. The roads are well-graded and would be lots of fun (and much faster) to bike down!
Note #2: The following route description was updated in 2010 when a friend pointed out some minor changes in the logging road approach since I did the route in 2006. As is typical in the mountains, route details are always liable to change, so take this info with a grain of salt that grows larger with each passing year.
The map above shows the route outlined in red. I have added some comments to the map to point out some notable landmarks. Here is a brief description of the route from the gate:
The route up the West Ridge as seen from the clearcut area.
Looking up towards the obelisk on the West Ridge, about halfway up the climb. The Twin Sisters are actually the largest body of exposed olivine in the Western Hemisphere. The rock is called dunite, and it is super grippy and is some of the best climbing rock in the North Cascades (Beckey, pg 41).
The view west down the west ridge. The climb gives a great view of the San Juan and Gulf Islands.
The South Twin Sister and the North Cascades from the summit of the North Twin. I got to the summit in 2.5 hours from the car.
Looking down the North side of the North Twin from the summit. In the earlier season, some people descend by glissading down the north side of the mountain (although others have said it is too steep to do so - as I tend to prefer rock to snow, I might side with this opinion depending on the snow's condition), but without the snow cover it looked too loose to be much fun, so I just descended back down the ridge (1 hour from summit to treeline for me, 1 h 15 minutes more to my car (now I wished I had a bike to bomb down the roads!)).