Mt Muir, located in the Eastern Sierra about 2km south of Mt Whitney,
is one of the highest mountain in California
(4272m) despite being hardly known.
Follow the directions for the regular trail of Mt Whitney. After the junction with the John Muir trail, continue up the Whitney
trail for about 500m to a wide sandy gully.
There is nothing to mark the spot but this is how it looks like from the trail:
Mt Muir is only about 100m higher than the trail, but those are almost
vertical meters. If you find the easiest route, it will be all class-3
climbing with scary exposure. The trick is to find the two chimneys
that help bypass a chockstone.
The first one is located at the far right as you are staring up from the trail.
At the top of that chimney move to the left: find a gap between two stones that you can use to hold yourself and traverse over a very steep boulder. once you are in the second chimney above the chockstone, the rest should be obvious: head to the right and up.