Letter books, which contained copies of all outgoing correspondence, were once common items at all posts on the upper Missouri, but only a few survive today. Those that do vividly illustrate the nature of commerce on the Northern Great Plains during the first half of the nineteenth century. Michael M. Casler and W. Raymond Wood have transcribed and annotated these rare documents.
Letter books, which contained copies of all outgoing correspondence, were once common items at all posts on the upper Missouri, but only a few survive...
