Since this route is recommended only as a snow climb, you may be attempting it when the road isn't open to the summer trailhead. The lowest winter closure is near 9,200' - over 3 miles below the summer trailhead. In spring and early summer, you may be able to drive to the Harvard Lakes trailhead, a bit farther to the Silver Creek TH (1.5 miles below the North Cottonwood Creek TH) or even farther. Park and hike to the upper trailhead at the end of the road.
Taken from Mt. Yale,
1 shows Columbia's southwest couloir. Follow the standard trail for over 3 miles to approx. 10,950' where the summer trail (if you can see it) reaches a small stream crossing. Turn right and follow this drainage directly north through the trees. Continue another 1/2 mile to reach the large, open avalanche run-out area at the base of the southwest couloir (
2). This is a good place to take a few minutes to study the terrain ahead. As you can see by the size of the run-out, this couloir can produce large slides and it's not a place to be when snow conditions are poor. Hike toward the base of the couloir (
3 and
4) to reach the "choke" at the base (
5). The lower half of the couloir is no more than ~28° in angle and can usually be done with skis/skins or snowshoes but the upper half can reach ~32°.
After the choke (
6,
7 and
8), continue to evaluate snow conditions and decide whether to continue in the couloir (
9) or exit left and parallel the couloir on its west side (
10). Climb northeast up steepening terrain as you approach the ridge above (
11,
12 and
13). If you stayed left of the couloir, you will intersect Columbia's standard, west slopes route above 13,000'. Near 13,400', angle left to hit the ridge, west of the couloir's flat top -
14.
Once you reach the ridge (13,600'+), the remaining hike to the summit comes into view (
15). Turn left and follow the summit ridge over rock bumps and small saddles. From where you hit the ridge, it's over 1/2 mile to the summit. After a few ups and downs, cross a flat area (
16) and climb the final rock pile (
17) to the true summit (
18).