Suggest me a book to read while trekking the Himalayas

I'm spending about a month on lesser-known mountain treks in the Himalayas and would love a book with a natural or mountainous backdrop. It can be a non-fiction peaceful reflection about nature or even a fictional adventure that takes my mind away from urban life.

Some of the titles I've been thinking of:

Walden – Henry David Thoreau

The Snow Leopard – Peter Matthiessen

The Lord of The Rings

Would appreciate any other recommendations!