Book #14, The Way West, and #15, Fair Land, Fair Land, by A. B. Guthrie Jr.

These are the last 2 books in the trilogy.  They give a fascinating look at, firstly, the rigors of taking a wagon train to Oregon, and, in the finale, the somewhat  melancholy life of an aging man of the West who knows his day has past, and the life he loved is about to be replaced by settlers and towns.  Highly recommended.