Thank you for the info, Sven. There were several Arapahos called Left Hand we need to distinguish. Actually two men of that name were important Southern Arapaho chiefs. The older, brother of Neva, died at Sand Creek. He is the one mentioned in the new book.
The man John and Grahame speak of is the Northern Arapahoe Left Hand. He was present at the battle at Little Bighorn in 1876.