From the trailhead
, follow the well-maintained trail paralleling Stewart Creek into the forest (
1). After 2 miles, pass faint remnants of an old log cabin on your left. Pass beaver ponds and dead spruce trees as the trail gradually ascends into upper Stewart Creek (
2). Near 3 miles, the trail weaves through willows and may be harder to follow in spring or after recent treefalls. Around 4.25 miles in, at 12,000', the terrain opens up as you approach tree line (
3). Continue southwest toward the upper basin.
Near 12,300', turn south, descend to the creek, cross it, and hike through more willows to the base of the broad slope
below the saddle between 13er Organ Mountain and San Luis Peak (
4). Begin your ascent to the saddle. Gain approximately 800 feet of elevation over 0.8 miles by following the excellent trail with switchbacks (
5,
6, and
7) to reach the saddle
at 13,100' (
8).
Walk across the saddle to the south side of a large point on San Luis' northeast ridge (
9). Traverse westward toward the ridge crest (
10,
11). Near 13,750', gain the northeast ridge
and cross to its west side (
12). Follow the trail back to the ridge crest (
13) and to the summit (
14,
15).