I read the first book in this series, The Big Sky, many years ago in an old Time-Life series of out of print books. It was very good (also a movie with Kirk Douglas, I think), and I wanted to read this sort-of sequel, especially since it is on many lists of the best westerns. However, it is not available as an e-book, so I did not read it out of principle. I recently realized that I wasn't sure what the principle was, so I bought a used paperback copy. It's quite good. I recommend that you read it with a copy of the Oregon Trail Map that the national park service has. You can download it as a .pdf file. Now I have a paperback copy that nobody wants, so if you are interested, I will give it to you.