From the trailhead at the upper reservoir, a trail begins at the NE corner of the reservoir that leads into the unnamed, steep-walled basin on the west side of Quandary Peak. The trail angles uphill WNW, gaining elevation above the reservoir quickly, passing through some willows, then crossing the lower tongue of a talus field. Once past the talus, the trail heads more NW on a tundra slope, cutting through some more willows and staying on the right hand side of the creek, following the remnants of an old mining roadbed. After a while, the trail crosses to the left side of the stream, passes some meanders and becomes wedged between talus fields on both sides of the narrow valley.
When the trail comes to something of a headwall, the stream descends from the right, but the trail follows a narrow, tundra gully more to the left and crests out at a small pond. Here is where you now have the two options. If you continue in the bottom of the drainage NW for a little longer, you can scramble on out through rock outcrops and talus to the left and emerge onto a flatter plain below the SE ridge of Fletcher which connects over to Quandary. Gain the ridge west of an unnecessary bump and then hike on Class 2 rubble to the Fletcher summit.
Alternately, (and this is how we did it), from the vicinity of the same small pond, begin immediately to leave the drainage bottom, heading more to the left and hiking up rubble and past some rocky outcrops, following a wider gully that may hold some snow until you once again emerge onto the high plain that sits below the Fletcher summit on its' south flank. Stroll across a combination of tundra and smaller rubble and embedded rocks toward the Fletcher SW ridge and a saddle. A low, rounded ridge marks the south terminus of this high plain with a PT. 13,515 marker on the survey map. Keeping that ridge on your left, use it as a guide for reaching the SW ridge. There are any number of ways to go up, but for now, you may want to avoid the yellowish slope farther right that holds the kind of scree best for descending, but more of a pain to go up.
Once on the SW ridge, it is again, a Class 2 rocky stroll to the summit where you can enjoy an impressive view of Quandary and its' Class 3 west ridge. Stronger and more skilled parties may want to consider the rugged traverse to Atlantic Peak, north. Otherwise, descend by either route you ascended or make use of the yellowish rock/scree slope for a quicker descent back to the plain. Or, if looking for something challenging, consider a trip over to the summit of Drift Peak, a soft-ranked summit to the south that offers a very sporting route.
Links to other information, routes & trip reports for this peak that may be helpful.