Islands in the Snow: A journey to explore Nepal's trekking peaks

Two days east of Lukla was a pleasant yak pasture surrounded by high peaks. When Col. Jim Roberts set out to look for it in 1953, he ended up making the first ascent of Mera Peak and sowing the seeds of Himalayan tourism.

Mera Peak has become a popular goal for trekkers and novice mountaineers, but few people climb to its true summit, and fewer still travel beyond it to find the secret yak pasture that sparked Roberts' journey.

The yak pasture was the Hongu Valley, a hidden sanctuary of grass...