The Great Himalaya Trail is a proposed trail of more than 4500 km stretching the length of the Greater Himalaya range from Nanga Parbat in Jammu & Kashmir to Namche Barwa in Tibet thus passing through Kashmir, India, Nepal, Bhutan and Tibet. When completed, it will be the longest and highest alpine walking track in the world …
It will never be “completed”. There are many GHT routes, higher and lower. They can be hiked continuously or by section.
Check out two main websites, both pretty good:
The second mostly covers GHT Nepal.
The guidebook I’m researching is from Trailblazer – Nepal Trekking & the Great Himalaya Trail 2011 by Robin Boustead.
He’s got a coffee table book, as well, that I’ve never seen – The Great Himalaya Trail.
Stuart Bilby solo’d the Nepal GHT Nepal in 127 days in 2014, an incredible accomplishment. No cars, buses, planes, donkeys or yaks for transport. Stuart lost 19kg body weight. Actually, the first half he did with Lisa Lee-Johnson.
Linda Bezemer published a (much more reasonable) GHT Low Route electronic guidebook which you could use with an iPad on the trail. 1550km broken into 11 sections.
Seth, Kathleen and John did a 2014 east-west GHT Nepal traverse.
But my favourite is Gerda Pouler’s account of her 2012 very personal adventure – Great Himalaya Trail: 1,700 Kilometres Across the Roof of the World [Kindle Edition].