I thought I'd share some details about this trail and scramble that I could not find on the web.
I don't pictures, but there's a lot here http://www.summitpost.org/north-twin/151345
The access from Vancouver is via
-> Mt. Baker Highway 542
-> Mosquito Lake Rd. This is a nicely paved two lane road with rural houses on both sides.
-> 'Middle Fork Road'. My GPS map was calling it 'Anacortes Veneer Logging road'. At the turnoff there was a giant pile of fine gravel. This is a well maintained logging road. No waterbars or holes but it's maybe 1.5 lanes wide, with some blind corners. Warnings for trucks and CB freq posted but I didn't see or hear any.
-> small turnoff towards a bridge. The bridge is gated, well locked and full of warnings. I parked here, natch.
I've uploaded the gpx track that shows the complete trail from the bridge all the way to the turnoff to North Twin Sister.
Map on the site:
The logging road is extremely well maintained. No holes, fine gravel, no waterbars, no braking bumps.
The uphill section begins immediately after the bridge and the grade is sustained for the first 80% of the route. The last section is still uphill, but easier. There are almost no flat sections.
I would estimate the road is anywhere between 8-12% grade
The trail that goes up from the end of the gpx track onward is absolutely fool proof. You can choose to push your bike up another 30min. I'm not so great on my hard-tail and this road is much narrower, has waterbars and it was steeper with looser gravel. You would save about 15min when you are returning if you are good at biking it.
Following, the steep and narrow trail enters the forest. It's 20min to a clearing and this is where the scrambling begins.
The rock is like 60 grit sandpaper, and it seems to be formed so there are almost no cliffs. I've tried to go off route and climb wherever I felt like, 'blind' to what is coming and there was always a way out. I did not see any 5th class moves that I was forced to do.
If you don't have climber hands, bring some gloves, because 2-3hrs of grabbing these holds will make your hands feel raw.
At this time, I would strongly advise to return the same way you went up, as this August the north side snow was melted away too much. The entrance is very steep and the rock very loose. Normally I don't mind shale, but this was quite sketchy.
I was also wondering what gear is needed, so if you're curious for late july-august-september:
- ice axe not needed if you return the way you came in
- helmet absolute yes
- 3L water min. There was water access but it was in the first 4km of the logging road. The north side has some waterfalls but it's out of the way if you're not going down that way. I took 2L on me and 1L on the bike. Saw at least four fire pits at different spots near the trailhead but could not figure out where they would be getting the water if camping, so maybe there's something around there.
- didn't need crampons
- didn't need mountaineering boots or climbing shoes, I went in hiking boots.
- didn't wear a shirt, or jacket. It was extremely hot the whole way. I don't burn, so YMMV.
- hiking poles would most likely just get in the way the whole time, unless you're hiking the logging road.
- for me, the crux was the logging road and going down the north face
- bugs don't care about bug spray
Total ascent was just under 4.5hrs.
- bike (gpx track) took 1h 20min. Biked most of it, granny gear.
- stash bike, 30min hike to enter forest
- enjoy the next 2-3hrs of the jungle gym for grownups to the top. I took my time here.
total round trip ~25km