Route: Southeast Route (3rd)

TR #: 37

Category: Washington (SR 542)       Summit Elev: 7,435 ft       Rock Type: Greenstone

Partner: Lisa Doubet

A fun autumn climb with my cousin. 

Map of our route from the Yellow Aster Butte trail to the summit of Tomyhoi (click to enlarge).

My favorite part about early autumn where I live is hiking in the North Cascades. So when September 24 looked like it would be a sunny and warm day, it was no surprise that I found myself planning a hike/climb with my cousin Lisa. The plan was to hike 3 miles into the Yellow Aster Butte area and continue up to Tomyhoi Peak, a Class 3 scramble about 3 miles from Yellow Aster Butte, near the American-Canadian Border. My Mother Sue, Aunt Barb, Uncle Scott, and Cousin’s Friend Kristen came along with Lisa and I to spend the day on the lower arm of Tomyhoi while Lisa and I climbed. We planned on a 9 hour round trip from the road for the climb, which turned out to be pretty accurate. Here is a brief timeline of our climb:

  • 8:45 am - leave trailhead (3,600 ft) of Yellow Aster Butte Trail.
  • 10:45 am - arrive at arm just below Yellow Aster Butte, around 5,200 ft.
  • 11:45 am - Aunt Barb, Uncle Scott, Mommy Sue, and Friend Kristen find a nice place on the lower Tomyhoi Arm to stay while Lisa and I climb.
  • 1:35 pm - Lisa and I arrive on summit (7,435 ft) (just under 5 hours from road at a relaxed pace).
  • 2:01 pm - Lisa and I head down from summit.
  • 6:05 pm - arrive back at car.
  • 7:15 pm - my mom and I arrive at the Sumas border crossing to find a lineup extending out the south end of the town, due to a murder suspect that is thought to be escaping into Canada. This was the longest border wait I have ever experienced. But at least we were able to get home eventually (apparently the timorous Blaine border crossing guards refused to work, saying that without guns they "felt unsafe" (a likely excuse--I think they all saw the nice weather and decided they wanted to go hiking. Perhaps this was why there were so many people climbing Tomyhoi—all those Blain border guards…)).

Below are some photos from the hike/climb. The autumn colors were beautiful.


About 2 hours from the car (2,960 ft), we arrived at the lake basin (5,200 ft) near Yellow Aster Butte. From here we could see the summit and the route up Tomyhoi Arm. It took us 3 hours to get to the summit (7,435 ft) from here (5 hours from the car to summit). Most of the climb was on a trail along the ridge, with a final Class 3 scramble up the summit block.

After following the trail up Tomyhoi Arm, we had to traverse around the north (right) side of the ridge and climb up to a notch in the ridge before the false summit. The hard snow around the small moat on this traverse was probably the crux of the route, but it was relatively straightforward nonetheless (ice axe but no crampons).

Lisa climbing the glacier-polished rock to the notch after coming up the hard snow of the small moat. (On the way down we discovered that the hard snow around the moat could be bypassed by traversing 100-200 ft lower and climbing up the rock finger to the notch. At least this was the case in late September 2006.)

From the false summit shortly after the notch, we could see the summit block. We had to descend about 100ft, and then do a fun Class 3 scramble up the left-center of the block; it took about 20 minutes to get to the summit from where the photo was taken. Notice the 4 climbers coming down. CORRECTION to route line in photo: In 2012, timmy_t from pointed out: " the photo where you have the 4 climbers circled (descending the class 3 rock rib), your red route line above them is incorrect. There is a chasm separating the rock above the top climber, so once you reach the top of the rib you go (viewer's) left, over to the shoulder, then up a step, then behind the rock... NOT straight up."

Lisa on the exposed class 3 scramble to the summit, Canadian and American Border Peaks and Tomyhoi Glacier in the background. This photo makes it look more exposed than it actually felt. This scramble to the summit was my favorite part of the route.

Is that a cantaloupe on the summit?

Summit view to northeast (Canadian Border Peak, American Border Peak, Challenger, Pickets, Ruth).

Autumn colors and Baker from Tomyhoi Arm. The entire hike we were treated to beautiful autumn colors.

Autumn colors and Baker from Tomyhoi Arm. The entire hike we were treated to beautiful autumn colors.

Autumn colors and Mt. Shuksan from trail between the car and Yellow Aster Butte. Such a beautiful area.

Autumn colors and Mt. Shuksan from the trail between the car and Yellow Aster Butte.

My mom hiking on the trail to/from Yellow Aster Butte, Mt. Shuksan in background. This trail is one of my family’s favorite dayhikes or overnights.