BETA PHOTO: Andrew following up the splitter variation to the ...
P1: start with a series of cracks starting near the west arete. There are many possible choices, but the left-most splitter is probably the easiest and great climbing. Continue until your rope runs out and belay from a tree. P2: Choose from many variations, and climb up to the ledge that separates the spire into two sections. This is referred to as the lunch ledge, and it is possible to skip the first two pitches by scrambling to this point from the ledges to the east. P3: Start directly under the small tree about 100 feet up. Take the "railroad tracks", where you'll find a fixed cam and a pin. Belay at tree with gear. P4: Continue straight up from here following cracks and flares to the large ledge(160 ft).Sling belay off block or gear. P5: From under the roof, move right out avoiding the roof to get back on the face. Continue past a few face moves(crux) to cracks, and finish on the next large ledge(160 ft). Sling Belay from Blocks or pro. From this ledge, walk north and around to top out.
Shoshone Spire. The route starts on the west arete of the south face, with a few possible variations. Descend by scrambling down the northeast side, continuing down to lunch ledge. From here choose a slung tree(there are a few), and set one double rope rappel to the base.
All Gear. Bring a rack of single cams to 3", and set of stoppers. One of the best aspects to this climb is the absence of bolts, save one fixed pin.
Just did it yesterday. Snow was a non-issue. Took us about 12 hours Missoula to Missoula. You can even probably rap off the Bonsai tree with a single rope. There is a slung block with a quicklink for an intermediate rap anchor. Might think about bringing some cord to back it up with.
1 Don't cross the creek too early. Best to find a crossing that leads to a direct shot up the talus to where you need to go.
2. Scout out the shortcut/walk off to/from the lunch ledge. It was really hard to find for us and we ended up rappelling.
3. The descriptions we had for the start were vague but there were a lot of options. The whole route is pretty vague, except for the start from the lunch ledge where there is fixed gear. But go with your hunch, it's all good.