The climb up Matterhorn Peak via Horse Creek Canyon and Horse Creek Pass from Twin Lakes is a real treat. It's what Jack Kerouac wrote about in The Dharma Bums. Along the way, there are several recognizable landmarks from the book. When I did it, we took it real easy and spent extra time, making it a four-day trip. But in the book they did it in an overnight, as you planned for Mount Langley, and I can see how it would be similar in terms of difficulty and effort.
