There is plenty of good information via Gerry & Jennifer Roach + Bob Martin & Mike Garratt on how to climb this peak. Their accounts both follow a similar, but convoluted sounding route that traverses the West & South faces of Potosi, finally climbing up a gully on the SE side of the peak. The target gully on the SE side of the peak is correct, but these accounts can be greatly simplified to avoid confusion. The short of it is to traverse across the west face of Potosi to a broad level area on the SW ridge below all the summit cliffs, then briefly climb this ridge up toward the summit cliffs before traversing across the S/SE face to the 3rd major gully that breaks through the summit cliffs. For a more detailed account, continue reading....
Assuming you're coming from the neighborhood of Coffee Pot, take a moment to survey the west face of Potosi. On the ridge extending toward you, if the snow has melted, you'll see a climber's trail taking off up the ridge that veers right—off of the ridge crest—well before the ridge intersects the cliffs. If you look closely, you'll see this trail lead across an area on the west face that is free of any major gullies or cliffs—gently gaining elevation at first before leveling its angle as it continues toward the SW ridge. Note a large, broad, level area on the SW ridge of Potosi that is comfortably below the summit block and the minor cliff bands immediately below it. You will want to aim for this spot, so take a moment to study the terrain and plot your course.
Carefully descend to the Coffee Pot/Potosi saddle. Along your way, there is a decent climber's trail that navigates this section—leading down & around several rough sections in the ridge. Use your best judgement to navigate this section and use caution. (Class 2+) Leaving the ridge crest, while at first reasonable and relatively fast-going, brings you into precariously loose & unstable terrain with an abundance of sharp rocks that are just waiting for an excuse to cut loose from their teetering position on the side of this slope. Tread carefully. You may be better off staying closer to the ridge crest, if possible.
Once at the saddle, follow the climbers trail up the ridge crest for a few hundred feet. The terrain closer to the ridge crest is again the most stable. Follow it where feasible until you either see the trail veering off, or until you see an obvious break between the spires and gullies of Potosi's lower south face and the upper cliffs that traverses comfortably over on a sloping bench to the level spot on the SW ridge. Follow the use trail and series of small cairns to this flat spot on the SW ridge. Nothing on this slope should exceed class 2 or class 2+. Avoid any temptation to gain significant elevation.
From the large flat area on the SW ridge, climb up the ridge crest for a short distance until easy class 2+ progress is no longer a reasonable possibility. Look for cairns and a use trail taking off across the S/SE face near the base of the cliffs. This trail will stay more or less near the base of the cliffs as it traverses east. Proceed to the first major gully that appears. If you're the adventurous sort, this gully may go. If you're a more conservative gambler, proceed onward. Pass a second major gully. Again, this may also go, but for the easiest route, continue to a third major gully. This one will be obviously wider, sandier, and more gravel-filled than the previous two. This is your route.
Follow this gully up for several hundred feet, but do not crest out at the top. Well before the top—perhaps 100 - 200 feet, look for a wide crack on your left hand side that breaks through the rock. We found this marked with a fairly substantial cairn in 2018. Follow the crack up to the broken terrain above.
At this point, Potosi's summit is only a couple of hundred feet away. Climb carefully up this broken terrain using a series of small ledges and cracks that break through the decomposing rock. We found a zig-zagging pattern of ledges that was easier to identify coming down. If you miss it, there are ample options for climbing up various cracks, but beware of the loose gravel on top of these decomposing rocks as a fall here could be serious. Above this slope, scamper a short distance on more even terrain to the wide, flat summit of Potosi.
To descend, unpack your hang glider or wing suit, measure the wind, and jump. This will be the best way down.
For those that did not pack an air-aided descent apparatus, retrace your route to the Potosi/Coffee Pot saddle and carefully consider your fate. We have been chided and castigated for what we show on the provided map in the light blue descent line. Please note, that line is only an approximation of what we did. It was difficult and intimidating. The darker blue line represents how our son and his friend descended. There are no easy, straightforward routes down from here. His description follows...
From the saddle, traverse gently right into a loose, rubble-filled gully. This gully splits into two branches separated by a rib/spire of rock. The right-most (Northern) side will most likely have softer scree to work with. The left (southern) branch looks to have larger, blockier choss to deal with. Pick your poison and drink deeply from it. Descend until you've cleared the cliffs. From here, you have two options:
- A contouring route to your right that rejoins the ascent route up Teakettle, or...
- A contouring route to your left that spills out (hopefully not literally) on the Yankee Boy Basin road a few hundred yards below where you started for the day.
If you chose #2, proceed as follows. (This description provided b Shaun Cooney from a 2018 descent.)
Exit the descent gully and begin angling left while carefully dropping a little lower. Aim for the top of a large area of gray dirt in the upper reaches of tundra just below the dark cliffs of Potosi's West face. There is a game trail that should be visible as it traverses across this slope. Find it and aim right for it, then use it to cross the gray dirt over into the tundra. The gray dirt is more of the increasingly familiar decomposed rock that sits at a precarious angle.
From the game trail, descend the tundra, aiming back to your right just a little. You're looking for the top of a specific gully. The easiest reference point is to find a gully with a small nub or finger right at its head that's visible from many angles. Set course just right of this mark to a small tundra protrusion that rests blissfully above the moiré of rubble below.
From this tundra, find a small ramp down into the gully (2+). Descend into the gully and proceed down carefully. When the gully briefly splits, the left branch is a bit more stable. Take it. You may be tempted to rejoice with glee as the terrain opens up and softens up below you. Don't rejoice yet. Proceed carefully in high-stepping scree dance down the slope a short distance (stay to your left). Before you reach the last wide-open section of this gully, STOP. You are only a few hundred feet above the road, but your are not safe yet. Continuing your high-stepping scree dance without careful observation will likely send you rocketing down out of control to the road below. While this slope, from above, appears to be more of the same soft scree you were just joyfully descending, IT IS NOT. The further right you go, the more this slope gives way to flaking sheets of rock covered in a thin veil of loose gravel that looks like scree from above, but is not. The pitch of the slope is enough to send you rocketing down the remainder of the gully were you to come into this section with any speed. DO NOT go to your right in the direction of a flat bench and more inviting-looking terrain. Instead, bear left toward a small strip of mixed tundra and rock. Step carefully. This terrain has a little more dirt below the veil of rubble than that to the right, but it can be difficult to distinguish what's truly dirt from the flaky, sandy rock that lurks below.
Once clear of the last cliffs, you may now rejoice! You're free of the rubble! Pick your line through a little more tundra, then a stand of trees, and continue rejoicing as you attain level, stable ground below the trees. Peer back triumphantly at your accomplishment as civilized onlookers gaze in awe. Intersect the road and follow to your vehicle.
If you choose #1, this is the descent route Tim & Carrie took in 1994. (The light blue line) Our notes were sketchy. Like Shaun, we returned around Potosi to the saddle below the 13,115 mark on the NW ridge of Potosi. Head down the very steep gully which splits as Shaun mentions. We likely took the more northern one which contained large enough rocks to be a hazard to one's health should they begin to tumble, of which several did. Bypass a rocky outcrop on the right. The gully will pan out onto a larger talus slope. At about 12,600 feet, begin to contour west to regain the track you followed up in the morning just off the ridge that leads up toward Coffee Pot. You will cross a few minor ribs. Once back on that SW ridge route that accesses Coffee Pot, simply follow your morning route back down.
On a final note, one climber using our descent route, after surviving a near-death experience, suggested that the best thing to do is to go from Potosi to the Coffeepot-Potosi saddle, then follow the Dave Cooper ascent route for Teakettle-Potosi-Coffeepot back down. At least much more of this has tundra farther down.
Links to other information, routes & trip reports for this peak that may be helpful.