"Route Bumthang to Trashiyangsi" refernece: Authority G. Sherriff and F. Ludlow. July 1933. Map Ref. Survey of India 1" to 4 miles sheets nos. 78I, 78M, 77P, and 77L. Note. The map names are in many cases wrong, and very often wrongly spelt. As far as possible, the correct spelling is there given, and map names are given in brackets. Heights are only approximate.", 3 pages, handwritten annotations in G.Sherriff's handwriting in pen.
9 marches, 91 miles
"The description of this route refers to the Summer months only. With the exception of the RUDO LA and DONGA LA it is every where good enough for laden mules. These passes are barely possible and are very difficult owing to the steep ascent over stones and slippery roots through the jungles on the West side, and owing to the extremely steep descent down rock steps on the East side of the RUDO LA...Note. The map names are in many cases wrong, and very often wrongly spelt. As far as possible, the correct spelling is here given, and map names are given in brackets. Heights are only approximate."
Sherriff, George