The William Graves Hoyt collection contains his published papers, research notes and correspondence. The publications cover topics such as the Meteor Crater in Arizona, Vesto M. Slipher, Northern Arizona University and Percival Lowell. Hoyt was working on a biography of Slipher at the time of his death, and his research notes focus primarily on Slipher's life and work. Correspondents include Art Adel, Bart Bok and Owen Gingerich.