What a great book to read to understand the history of The Overland Trail or The Oregon and California Trail. Includes details about the earliest mountain men and pioneers - names you do not hear about in our history. Loads of details about the Donner party coming to California - I did not know it could have been avoided. Being a person interested in true history I found this book to be very valuable in my personal quest. I have read many of these explorer's journals included in this book.