Basin Mountain
Posted: Wed May 23, 2018 10:50 am
GENERAL OVERVIEW: Moderately technical 13er visible and accessible from the Bishop area. From the trailhead at 8000', it's just over 5000' to the summit. There are dispersed camping areas (including the mine entrance) around 10500'.
CLASS/DIFFICULTY: 2, 3, or 4+ depending on the route. Expect snow in winter, spring, and possibly later; the east couloir in particular stays snowy into the summer. Crampons and ice axe are recommended.
LOCATION: Inyo National Forest. See the HST Map.
ELEVATION: 13180 ft (4017m).
USGS TOPO MAP (7.5'): USGS Mount Tom quad.
ROUTE DESCRIPTION: Approach from the Horton Lakes trailhead at the end of Buttermilk Road. Note: 4WD & high clearance vehicle required if you want to park right at the trailhead.
For the east couloir, follow the old mine road up switchbacks to a broad basin. A more direct cross-country approach saves time if snow cover allows. From the basin, ascend the 30-40* couloir to the notch. From the notch, the most direct route to the summit is a ~300' class 4+ scramble with non-trivial exposure.
Alternatively, cross over the notch and head north (right) for a class 3 traverse around the west slope of the summit block to a steep south-facing scree slope. From the ridge, it's ~100' of class 2-3 slabs to the summit. This route also makes a good descent option for the 4th class route.
I'm told there's also a class 2 route up the north slope from Horton Lakes, which might be preferable for late summer or thin snow years, when the east couloir is just scree.
Lastly, I heard someone put up a 5.8 route up the obvious left-facing dihedral starting near the top of the east couloir, but I don't have details.
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