Anyone know if this N. Milestone Basin pass is a GO?

[michaelzim]

Daisy.....Yes, it would be much easier to figure the feasibility of this "gap" if someone had been over it. And therein lies a bit of an answer to "why do it in the first place?" Ummmmmmmmm...'Because it's there' is kind of lame, but for sure there is an element of: 'for the adventure of it' in my ponderings here. It's kind of fun looking at maps in the safe confines of home dreaming of exploration - that may indeed get severely curtailed in reality.
If all goes to plan I will have been on trail for a while before attempting this route over the ridge so could be "acclimated" enough by then to consider it with a pack. My adventure capability is a lot more after about 5 or 6 days backpacking v. the first few days in particular.

As to elevation gain and such I get some different figures, mainly due to starting location.

If I am camped at that lake where you photo icon is the CalTopo cursor elevation in the top right box = c. 11,930 ft.
The lake on the Kern River downhill to the east at the bottom of the valley = c. 10,680 ft. So a drop of...1,250 ft.
From that lake on the Kern to that uppermost lake in the northern basin at 12,310 = 1,630 ft. gain.
So total via the 'round the ridge' route, just in elevation change = 2,880 ft.

Now, if go directly from the camped photo icon lake up to the "gap" the numbers are...
Lake at 11,930 ft. and gap/pass at 12,840 ft. = a climb of 910 ft.
Then down to the upper basin top lake, presuming a traverse around that moraine works, would be 12,840 - 12,310 = 530 ft.
So total elevation change via the "pass" would be 1,440 ft. so half of the round the hump route, and much less distance.

I hope I got that right, but if so, it adds to the potential appeal so long as it is not a sphincter clincher with hairy exposure, etc., etc. And as you point out it does seem like this would have been found out and listed already if it were a go. So....?????????????????

Best ~ Michaelzim

[Wandering Daisy]

If you check it out, stay safe! Scout ahead without a pack if needed. Perhaps take some cord to lower your pack if needed. Seriously, the topo does NOT look "easy" to me.

I doubt you will get information from backpackers. You could scour climbing reports (SPS reports come to mind) and see if anyone has been up the pass as a part of their climb. Gazelle's post says that one person climbed the adjacent peak from the north side, reported class 3. Still no information on the south side.

[Gazelle]

there are other pictures of it if you look at midway peak, thunder and table mountains just have to know what you ate looking at! daisy someday I am going up the peak only smatko has done, I have myself going up to the peak as a day hike from either side based on what I see when I get there and moving my pack around the ridge.

[erutan]

I've only poked into that area a bit and it's on my list to go back to with more time to spend - so this is an uninformed opinion just looking at topo. I feel like someone that does more westside trailheads has to have done this route or parts of it and can chime in if you're interested.

What about doing some dayhikes up milestone canyon, then taking your pack up the canyon between thunder and table mountains (it looked gorgeous from the bottom passing by Casper lake), then going thunder ridge / west thunder pass (secor class 2, modern 2-2.5?) and then wiggle over to Longley Pass (which shouldn't be corniced in this year, Secor 1 / modern 1-2?) and try and stay high around south guard lake to brewer lakes via Cinder Col (another 2-2.5 ( (big brewer lake seems like a tight shoreline, but the rest of the lines are pretty mellow), follow brewer creek then cut N of 9985T to the hit the trail going over avalanche pass around 8700ft then take that to bubbs (or just take sphinx col more directly).

You could also drop back down to reflection from Longley, but from what I remember from '17 that'd be pretty rough and not as loopy obviously.

[michaelzim]

Daisy & Erutan...Like Gazelle mentions too, looking at photos or even the plain topos is not necessarily that decisive for me, though for sure better than nothing. When I look at photos from afar routes can look impossible. Whereas closer up pics looking down a pass do not seem to do justice to the actual steepness or drop off somehow.
I find 45 degrees exposure with much downward distance to be quite unnerving. Hence the slope shading gives me a better feel for at least marginal possibility (as am not familiar with how to make Google Earth work for me on this kind of research).
That "Gap" at least seems to avoid the purple and grey zones, which are very likely to be no go's for me unless lots of grippy hand holds and no fall offs into space. A closer up of it:

The maybe Gap.JPG

Now compare this to the suggestion of "West Thunder Pass" - which I presume is MacLeod Pass on HST map:

MacLeod Pass.JPG

MacLeod has the same darker red and even some purple on the west side...Then has this description:
<p>Class 2 pass. Climb a loose chute on the west side of the pass. The eastern side is easy.</p>
That makes me go "Ummmmmmmmm", as on the slope shading "The Gap" looks less intense...All to say, that without a first hand report of someone doing it my skills for assessment end up within the current thread on re-classifying Class 2 and 3 passes more accurately! On paper MacLeod looks to me like a possible Class 3 in places with a good lot of 2.5...whereas the Gap looks like Class 2 with some possible 2.5 places. In reality, seeing as it is not in the list of passes so far implies that it may be a hairy option more suited to you mountaineer types. It sure offers a tempting shortcut for anyone heading north there so I would have thought it would have been used by now - if it was a go.
So we are back to - figure it out once there. And indeed, with my long section of heavy duty para cord and off pack scouting...IF it does not scare the pants off me just looking at it.

Erutan...MacLeod aside I have considered (and am still) a "west side" return and using Longley to drop back down to Reflection, and also getting to Bubbs Creek again via Avalanche Pass. There are a few trips reports that cover that ground I recall. However, it may be taking on more than I am capable of in terms of the size/length of the loop. I keep reminding myself that I reach too far at home and the uphill parts are much, much slower than they used to be. The west route has a lot more up-hills I think!

Thanks Much ~ Michaelzim

[erutan]

I dug into this a year or so ago - slope angle shading is based off a LIDAR space shuttle scans from a decade+ ago and are NOT 100% accurate. The Sierra generally has the most accurate slope shading possible, but that's still 9 meters of ground per pixel if I'm reading the resolution properly (9 m/px). In the southwest that can be 27m / px and can miss 50 foot cliff outs.

A 15 foot cliff out will stop your day and not show up - amusingly above the bottom of slide canyon heading to doe lake is an area that's really flat on topo (40ft resolution) and slope shading but contains sets of 15-20 granite fins that made it a labyrinth of Class 4. The yellow/orange slope heading up there was solid slab and far easier to navigate!

The upper part of Dragon on the SEKI side is steeper than 45deg, but once you cut over some 2.5 to the chute it's short switches down sandy ground then the angle mellows you when you hit stable talus - I found it a lot more straightforward than some lower angle terrain with sliding talus or lots of 2.5/3 obstacles to mantle/climb.

You can bake in some time to scout without a pack, or try and have a "failsafe" fallback plan if a more adventurous route doesn't pan out. I'd probably stick to stuff you can find write ups on, at least as a fallback. I'd check for write-ups on all the passes in the area you can find. I find that a region/crest will have similar characteristics and one can (with uncertainty obviously) make some reasonably educated guesses on nearby terrain based on what's nearby.

Agreed that a loose chute that steep sounds like garbage, especially if you have loose talus in it.

update:

Some related TRs:

viewtopic.php?f=1&t=21304

viewtopic.php?f=1&t=20388

viewtopic.php?f=1&t=20370

XC Pass entries:

Cinder Col viewtopic.php?f=31&t=12188

Longely Pass viewtopic.php?f=31&t=8466

Brewer Pass viewtopic.php?f=31&t=19076

Thunder Ridge Pass viewtopic.php?f=31&t=8462

Talus Pass viewtopic.php?f=31&t=8461

[Wandering Daisy]

Slope angle is just the overall slope. It does NOT account for cliffs and ledges. The metric contours will not show a 30-foot cliff! The newer metric maps are generated by DEM data and computer extrapolated and "smoothed" from satellite data. I find the that old hand-generated 40-foot contour maps were more detailed because a human with geomorphic training did the extrapolation. The overall slope is usually valid if snow covered, so good information; but I would not do 45-degree snow without an ice axe. 45-degree scree is above the angle of repose and may be unstable. Are you comfortable on a 45-degree rock slab? Based on the day-hiking and climbing I have done in both basins I found the micro-topography quite complex and cliffy. It may take onsiderable scouting to find a route that goes.

If you go over Longley Pass, the shortest route is to drop to Brewer Basin and over the pass to Sphinx Lakes. Tricky route down to Avalanche Pass Trail but lots of information out there; several recent trip reports. Wonderful route.

Sorry to repeat the post above, but you beat me to it!

[erutan]

Yeah I'm always sad when I lose my 40ft hand drawn lines and just have 20m ones aside from having less resolution (~66ft vs 40ft), smoothed is a good way to put it. OSM based maps are using the same data that slope angle shading does. My default digital backpacking map is the classic hand drawn USGS with some light slope angle shading and shaded relief on top.

This is my favorite OSM / slope angle shading glitch. The Paria river does not actually flow up and down a 120ft saddle, the canyon walls continue as one would expect (and it's not even super slotty). The USGS map depicts them correctly. Interestingly shaded relief seems to be correct.

Screen Shot 2022-03-28 at 1.18.12 PM.png

I figured there'd be some good beta on that route - if it calls to me on Topo it must have for others. I've been wanting to go up the canyon from Caspar since '17 - good to know I'll plan for slow days when I get around to that area.

[Wandering Daisy]

First time I ventured above Casper Lake I met some old fishermen who referred to this valley as "Rainbow Valley". They also said "shh!! do not let anyone know about it!" You will not be disappointed. There is good camping in timber north of the creek, before you get to the waterfall and headwall. Also good camping just up the small cliff at the NW end of Casper Lake. I think I would drop down from Milestone regardless of the extra distance and elevation just because I love this area so much. Climbed one of the ridges (south, I think) of Thunder Mountain years ago with a SPS group. One of my favorite photos below. Second photo higher in the drainage.

0748_Surise_Casper Camp_edited-1.jpg

7483_Rainbow Valley_edited-1.jpg

[frozenintime]

they are slowly updating existing slope angle shading with new, much more hi res stuff. desolation is the only part of the sierra that i’m aware of with the new slope info, and it’s pretty striking compared to the blocky stuff we are used to.