File:Kathmandu To Mount Everest Approach March, Bonington 1975.svg
Cropping and annotation by uploader, own work.
The red line shows the road existing in 1975 and the black line is the route taken by the 1975 British Mount Everest Southwest Face expedition as described in Bonington, Chris (1976) Everest the Hard Way, London: Hodder and Stoughton ISBN: 0340208333. .
The base map shows the then (indeterminate) border so the annotation shows the contemporary border from the Times Atlas/ Google Maps.
http://www.lib.utexas.edu/maps/ams/india/ng-45-02.jpg http://www.lib.utexas.edu/maps/ams/india/ng-45-01.jpg http://www.lib.utexas.edu/maps/ams/india/nh-45-13.jpg
http://www.lib.utexas.edu/maps/ams/china/txu-oclc-10552568-nh45-14.jpg