Drive State Highway 542 east from Bellingham to Glacier, then another 13.5 miles to some highway maintenance sheds (46 miles from I-5) Just past mile marker 46, turn left on Twin Lakes Road and drive it for 4.5 miles. Right before an "end of maintained road" sign is the "Yellow Aster Butte" trailhead.

Tomyhoi & Yellow Aster Butte Your online resource for hiking, climbing and travel
Distance: 5 miles
Elevation Gain: 5,000+ feet
Summit Elevation: 7,451 feet & 6,241
Access rating: Level 2
The Route:
You're going to love this hike and climb. The alpine area is reached fairly quickly, the views of nearby peaks are incredible and the summit area looks technical but isn't. Tomyhoi is just south of the U.S.- Canada border, in the scenic area north of Mt. Baker and Mt. Shuksan. The meadows and lakes below the summit make for some good camping. Nearby Yellow Aster Butte is a quick and easy side trip for others in the party not wanting to do Tomyhoi Peak.
Washington Cimbing
American Border Peak
American Border and Canadian Border Peaks
Tomyhoi from one of the bumps
American Border and Mt. Larabee
Mt. Shuksun
Route goes up center draw
On the summit ridge
The final rock climb
Ridge trail
Tomyhoi Peak American Border Peak Tomyhoi Ridge route American Border and Mt. Larabee Yellow Aster Butte Tomyhoi summit rocks Tomyhoi summit rocks Tomyhoi route American Border and Mt. Larabee Mt. Shuksun Tomyhoi summit access Climbing the rocks summit ridge the summit Yellow Aster Butte map
Looking down the class 3 route, that's my stashed gear about 20 feet down
Extreme Ironing
My climbing partner is into Extreme Ironing (google it!)
On the summit
perfect evening American Border and Canadian Border Tomyhoi from route Tarn between peaks
Hike up the Yellow Aster Butte Trail to the small lakes west of Yellow Aster Butte. Continue north on a trail that gains the main ridgeline going north, northwest. This trail route will take you up and over a few bumps. Around 7,200 feet on the east side of the summit rocks, you'll need to do some steeper climbing up a draw to reach the summit ridge. Once on top, a western traverse will get you to the final summit rock. This is a steep class 3 rock scramble but with good holds. See pictures for best route.
A perfect evening
My dog went down there to cool off
On the ridge
American Border and Mt. Larabee
Climbing the rocks
Small lakes west of Yellow Aster Butte
Tomyhoi from Yellow Aster Butte
Views near summit
Looking at the route below the summit rocks