At the trailhead, you may want to take time to examine the west and southwest flank of Twin Sisters West, identifying cliffs and areas of talus you may want to avoid later on. From the trailhead for the Rico-Silverton Trail, head south for about 2/3rds mile to the open area on the USGS map identified as "South Park." The "park" comes shortly after crossing a tributary side stream that flows from the west facing basin between the two Twin Sisters summits. In early season, unless the Forest Service has constructed a "bridge" of some sort in recent years, stream crossings may be difficult, especially when you initially have to cross to the east side of the South Fork. The flat meadow can be rather boggy as well and you may encounter more bogs in South Park. From the park, ascend SE, leaving the trail, up the steepening hillside through trees to something of a bench area between 11,600 - 800 feet, mostly covered with rock talus. From that bench, ascend even more directly to another bench or small bowl at 12,100 ft. where contours open a little. This is a little north of directly west from a saddle south of Twin Sisters West.
Continue your ascent on ever steepening terrain into a shallow couloir that will lead to the saddle just mentioned. 800 feet of more gain will bring you to that saddle. If later in the season, most of this will be on unsteady talus. Early season climbers may find the couloir snow-filled, thus avoiding much of the talus, but ice axe will be handy and you'll be doing a lot of tiresome kick-stepping. Once at the saddle, walk with greater confidence to the summit of West Twin Sisters over a much easier ridge. To climb Twin Sisters East, continue from the west summit NE, following the connecting ridge to Twin Sisters East, the higher of the two summits. The traverse will take about a half hour. The descent to the connecting saddle will be on some tundra with more rubble and talus. The final ascent will be mostly more tolerable rocky rubble.
If you're contemplating or actually working on climbing all the 13ers, then continuing on from Twin Sisters East to UN13,042 (V7) would make a great deal of sense. If not, you can return by the same route as you came or return by the following alternate route to climb these two summits and V7:
Alternate Route: From the Rico-Silverton TH, drive back down the road about one mile to a place with an old, unused road veering off to the left at about 10,600 ft. A trail is marked by a small cairn on the side of the road near this location. Appx. coordinates are: N 37° 47' 29.80" W 107° 47' 37.95". It leads down to the creek, losing about 100 feet, and then begins climbing on the other side. This newer trail appears to be used by the Silverton 100 as part of their route. This trail does not show on The San Juan NF map, the USGS quad or the Trails Illustrated #141. It does show on a "Drake Mountain Map" published in 1997 titled: "The Mountains of Silverton, Telluride and Ouray." At the creek, we had to take off our boots and wade across before getting underway. After climbing up about 100 yards or less, the trail joins another trail that parallels the east side of the creek.
Above the creek, the trail follows along the forest edge and begins climbing steeply along the north edge of a steep, shallow gully with no water. (May have running water earlier season.) The steepest hiking was in this section where we gained well over 600 feet on a series of switchbacks. Around 11,200 ft., the trail moderates some and begins to contour more, winding through the forest, crossing a minor ridge and then bringing you out into a clearing at the foot of a great, rock glacier. Follow the trail down some to the east, crossing a flower filled basin with some water in a small stream and then contour through more forest to a crossing of Porcupine Creek. Before this crossing, we passed through an interesting area of great boulders, covered in moss and other plants, that had fallen from cliffs far above, many ages ago.
On the other side of Porcupine Creek, the trail climbs east, then south through a field of gorgeous flowers, mostly blue columbine, paintbrush and assorted yellow, daisy-like blooms. The trail climbs up one switchback into a small, level area, ascends another rock band and emerges at yet another large, level meadow. From here, head for the pass at 12,200 ft. on the eastern flank of Twin Sister East. The entire area is laced with elk trails. From the pass, ascend west along the broad ridge of Twin Sisters East over mostly mixed tundra and rock giving way to rocky rubble as you hike higher.
From the summit of Twin Sisters East, you can easily traverse over to Twin Sisters West and return, taking only about an hour to do so, over mostly rocky conditions.