Upper Basin Crossing (UBC)

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cgundersen
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Upper Basin Crossing (UBC)

Post by cgundersen »

General Overview: UBC provides a conduit between the Upper Basin area (below Mather Pass) and Amphitheather Lakes Basin

Class: A challenging 2 with plenty of class 3 potential on the western face

Location: Kings Canyon National Park just southwest of Mather Pass

Elevation: 12,227 ft

USGA Topo map (7.5'): Split mountain Link to UBC on HST Map

Route Description: We approached from the east during mid-June of a low snow year (2012), and the ascent was uneventful with moderately solid footing on rock and some talus. We aimed for the low point on the ridge and dropped packs to search for a descent on the appreciably steeper western side. Roughly 100 ft north of the low point there is an angled granite chute that could be an option for skilled climbers. It drops ~100 ft to the extensive boulder field that constitutes most of the western descent. Instead, we found a series of ramps and ledges that began ~50 ft south of the low point. This system trends south and after descending ~100 ft, there is a lateral traverse back north that leads to a point just below the angled granite chute mentioned above. We got onto boulders at this point and continued the descent. It is a pretty arduous stretch of down climbing before you hit solid footing, and if I ever go this way again, I'll take more breaks to rest my brakes!

I had trouble loading high resolution jpeg photo files, so I'll try reducing the file size and add photos later.
cg

Distant view of UBC from the East
1.jpg
Final eastern approach to UBC which is the low point on the ridge to the left
2.jpg
Attachments
View of UBC from west.
View of UBC from west.
Ramp near the top from the west
Ramp near the top from the west
Views from the western ascent
Views from the western ascent
Amphitheater Lake Basin from UBC ridge:
Amphitheater Lake Basin from UBC ridge:
Upper Amphitheater Basin from UBC ridge
Upper Amphitheater Basin from UBC ridge
View East from the UBC ridge toward Split Mountain
View East from the UBC ridge toward Split Mountain
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cgundersen
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Re: Upper Basin Crossing (UBC)

Post by cgundersen »

I'm going to add a few more photos to highlight both the "fast" way off the ridge, for folks comfortable on granite ramps, and the more-conservative path we took to get to the monster talus field that preceded getting down into Amphitheater basin. I drew in annotation on a couple of the images.
Another shot of the final climb up from the East (Upper basin side)
Another shot of the final climb up from the East (Upper basin side)
West side view of UBC with the ramp on the left and zig-zag route we took
West side view of UBC with the ramp on the left and zig-zag route we took
Greater detail of the top part of the crossing from the West
Greater detail of the top part of the crossing from the West
Close up of the western ridge of UBC
Close up of the western ridge of UBC
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erutan
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Re: Upper Basin Crossing (UBC)

Post by erutan »

This pass was named “Amphitheater Pass” (3720 m+; 12,160 ft+; 1.5 mi NW of Vennacher Needle; UTM 680977) in 2009 by Secor. According to this trip report as of 2007 https://climber.org/reports/2007/1718.html Greg Gerlach named the pass "Amphitheater Pass".

It's a more accurate name IMO, as Upper Basin is pretty large and crossing is somewhat ambiguous and this is an actual pass. I'd say that UBC is more of an alternate name Ala http://pikazone.com/Split_Mtn_2012/ This pass was Amphitheater Pass, also known as “Upper Basin Crossing” by some.
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