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Thunderbolt Pass to Mt Sill

Posted: Thu Jul 08, 2010 3:02 pm
by ToddC
Anyone been over Bishop pass and Thunderbolt pass recently? Will be going July 24 to climb Mt Sill from the west. A quick word on conditions would be appreciated. Thanks

Re: Thunderbolt Pass to Mt Sill

Posted: Thu Jul 08, 2010 3:46 pm
by giantbrookie
You still have over two weeks between now and when you plan to go, so current reports won't necessarily project to what you will encounter when you go, given that a lot of snow will melt off between now and then. I'd be willing to bet that you'll be fine as of July 24 but you may have to trudge through some snow over Thunderbolt Pass on the Dusy Basin side. In late July 1993, which I believe was a heavier winter than this last one, I was up at Dusy, then went over Knapsack en route to Amphitheater and the Dumbbells. Dusy Lake 11393 was rimmed with snowbanks and had only been thawed a few days as of my arrival there in 1993. I'll go back and look up my old photos and see what Thunderbolt looked like then. Thunderbolt is not one of those passes that gets blocked with very steep snow because it isn't a very steep pass. However, if you have to posthole some distance in soft snow it will slow you down. This can be an issue if you are trying to dayhike Sill from Dusy as I did when I climbed it in 1984. That long dayhike is notorious for folks getting caught in the dark trying to complete it even in ideal conditions (I recall reading a couple of Sierra Club trip reports in the late 70s/early 80s to this effect and one of my professors at Davis had a similar experience). I made with time to spare in '84 (detoured to fish Barrett Lakes on the way back in addition) but I was hiking in beautiful early September conditions with no snow. This may dictate the slog over the pass (either Thunderbolt or Knapsack depending on your taste) with the full pack to set up base camp in Barrett Lakes so your summit hike is shorter.

Re: Thunderbolt Pass to Mt Sill

Posted: Thu Jul 08, 2010 5:12 pm
by ToddC
Good point about two weeks out and melting. Just trying to get some early insight. It's the "I haven't been to the Sierra since last Sept so I am anxious to get back" feeling. The plan is to go over Thunderbolt day 1 to set base camp and summit from there the next day.

Re: Thunderbolt Pass to Mt Sill

Posted: Thu Jul 08, 2010 7:50 pm
by Timberline
Hey, ToddC!

I don't have any current info about conditions, I just want to cheer you on. I did this hike in '78 with 3 friends and it turned into one of the best Sierra experiences I can recall, so I hope you enjoy your time at the feet of the Palisades, no matter how it turns out. At that time, we didn't make it to Mt. Sill's summit due to weather and our (neophyte) lack of preparedness, but the trip was a winner nevertheless.

Enjoy every minute of it! Share some pictures? That would be great. :nod:

Re: Thunderbolt Pass to Mt Sill

Posted: Thu Jul 08, 2010 8:49 pm
by Wandering Daisy
Second try at this reply! Doesnt it make you mad when you accidently push a key and your nearly done post disappears!

I climbed Sill from Barrett Lakes many years ago. I have also gone over Thunderbolt Pass four times, both early (4th July) and late (August). The north side is actually easier with snow. We made it to Barrett Lake in an 8-hour day, hauling in climbing gear. The descent to Barrett Lake is a bit tricky - just zig-zag - it should be relatively easy going , if not, you are off route.

When I was camped at Barrett Lake at the end of an 18-day solo trip, someone pointed out Sill and said it was a good climb. I thought he was pointing at Sill; he was pointing at the unnamed peak in front of Sill. So, stupidly, I headed up and climbed the south ridge, getting into some really hard climbing, topping out to find the summit register inform me that I was on the wrong peak! Sill lay across the valley. I traversed over deeply sun-cupped slope (I had not brought ice axe or trekking poles and had on tennis shoes!). I finally did the ridge to Sill and met two climbers on top who had done the technical route. I returned via Potluck Pass, traversing to it. Later I discovered that the little extra mileage to go to the west side of Potluck Pass avoided much difficulty. I got back about dusk. I was totally aclimated so was able to move quite fast. It is a long day. So, lesson is that be sure to check your map. On another trip I took two fellows over Potluck Pass. They wanted to climb Sill (I had just taken them up North Palisade, but I did not want to do Sill again). I sent them on their way, and I poked around photographing. They got totally off route and climbed a subsidery peak. The route is not that obvious.

Re: Thunderbolt Pass to Mt Sill

Posted: Fri Jul 09, 2010 9:32 am
by DAVELA
Wandering Daisy wrote: Doesnt it make you mad when you accidently push a key and your nearly done post disappears!
Ctrl+Z will bring u back to your previous step.Has saved my ass many times.

Re: Thunderbolt Pass to Mt Sill

Posted: Fri Jul 09, 2010 11:52 am
by ToddC
I climbed Agassiz last July and thought about continuing on to try Sill. I had 3 days. I mapped out the route pretty well. For some reason, that first day hike to Dusy Basin and climb beat me down more than most. And is wasn't an unusual Sierra trip for me. I am one of the lucky ones that are not affected seriously by altitude. Just occasional mild headache. I think a bunch of minor factors like should of had just one more litre, should have started off slower from South Lake, and not being in as good of shape as usual because I had stopped running weekly for a few months to recover from an achilles injury all caught up and fatigued me and kept me from trying to get to Barrett Lakes after Agassiz. I am ready to go this time! Some folks said instead of Potluck pass, head east and go over the ridge to the left before Potluck pass. Sounds like a good idea. Appears to save some distance and puts you close to the base of Sill. That's the plan.

Re: Thunderbolt Pass to Mt Sill

Posted: Thu Jul 15, 2010 12:18 am
by windknot
Hi Todd,

As of July 13, there were still patches of snow on the shadier switchbacks north of Bishop Pass but it was easily navigable and the snow had melted considerably from the levels we saw coming up the pass on the 8th. Didn't go up Thunderbolt but took a good look at it from Dusy 11393 and there's still a lot of snow. It should be manageable even if not completely snow-free by the end of July, so I think you'll be good to go.

Matt

Re: Thunderbolt Pass to Mt Sill

Posted: Thu Jul 15, 2010 8:44 am
by ToddC
Thanks, Matt.

Re: Thunderbolt Pass to Mt Sill

Posted: Thu Jul 15, 2010 7:49 pm
by giantbrookie
ToddC wrote:Some folks said instead of Potluck pass, head east and go over the ridge to the left before Potluck pass. Sounds like a good idea. Appears to save some distance and puts you close to the base of Sill. That's the plan.
This is the most efficient route, and this is the route I took to finish, but the key is in the details of the execution. You can see the route easily on the topo: You aim to cross the lowest point of the shoulder NNE of Potluck Pass (this is the SE ridge of Peak 13920+ SW of Sill or you can think of it as the ridge running NNE from Potluck Pass), at an elevation of approximately 13200', just above the dropoff to the SE. This not only makes sense topographically (the higher up this ridge you go the more elevation you have to lose to drop into the valley below Sill), but it is also the easiest to locate visually while out there because the dropoff of the end of this ridge at 13200' is very easily visible. When you crest out at 13200 you can keep the elevation loss to a minimum with a bit of contouring, or, if you don't like talus sidehilling, then you can simply go ahead and lose elevation by proceeding directly into the valley beneath Sill. Once beneath Sill, there are many options, of course, and you can visually size up the route you prefer to finish. Most routes will encounter a little bit of low 3rd class, but nothing hairy.

Best wishes for a great trip. Sill will reward you and justify its reputation: The summit view is one of the greatest in all of the Sierra.