From Lake City, drive 2 miles south on Colorado 149 and turn right on the Lake San Cristibol road (County Road 30). This is the southern entrance to the "Alpine Loop" scenic byway. Follow the signs to Cinnamon Pass. Drive about 20 miles to a signed fork in the road. Left is to American Basin and right is to Cinnamon Pass. Turn left. If you do not have a 4WD vehicle with good clearance, park in the pull-offs near the start of this road. It's 0.9 mile to the trailhead from the start of the American Basin road. After 0.2 mile, cross a stream which can be fairly deep in spring. If you don't feel comfortable driving through the water, there are some parking spots in the area. Continue to the end of the road where you'll find a large parking area and marked trail.
If you parked below the trailhead, walk up the 4WD road or the left side of the basin (Photo #1), to reach the area of the trailhead, near 11,600' - Photo #2. It's 0.9 mile from the start of the 4WD road/Cinnamon Pass junction to the trailhead. Continue south into American Basin - Photo #3. Follow the standard trail (or general location of it) to 12,200'. The trail climbs a hill ahead (Photo #4) but the west slopes route is not in that direction. Turn left to see the west slopes above and east - Photo #5. On the left (north) side of the slopes locate a long, broad couloir (Photo #6) that is used for this climb. Taken in summer, Photo #7 is another view of the area.
Hike northeast (Photo #8) over a drainage to reach the base near 12,300' - Photo #9. The climb from here to 13,100' is straightforward: Climb east up the couloir - Photo #10 and Photo #11. Taken near 12,700', Photo #12 provides a good look at the upper route. Above 13,000', the couloir broadens and the line to the summit starts to angle a bit to the right. Reach steeper terrain near 13,100' - Photo #13. The couloir averages 32 degrees and has a max angle of approximately 38 degrees, near 13,200'. Photo #14 and Photo #15 provide different views of the area. Near 13,300' (Photo #16), angle slightly right (ESE) toward the hidden summit.
The slope eases above 13,400' and the terrain flattens out as the couloir fades away - Photo #17, Photo #18 and Photo #19. Continue up flattening terrain toward the summit - Photo #20. Near the top, turn right and walk to the summit - Photo #21, Photo #22, Photo #23 and Photo #24.