The history of Marcus E. Jones' botanical travels, begins in 1876 in Grinnell, Iowa. He botanized all the western U. S., southern British Columbia and the northern states of Mexico. Our material includes a typescript copy of an autobiographical record preserved at Pomona College, “Botanical Exploration of Marcus E. Jones, 1875 to 1919”, p. 1-10, 25-34, a six-page breakdown of his “Itinerary for 1894,” prepared by F. W. Pennell in 1916, and two letters addressed to Pennell in 1917. Many references occur to other collectors and to obscure geographic localities which did not appear on published maps.