The library is home to the University of Wyoming's rare books collection, consisting of over 50,000 items and is sponsored by the Clara Toppan endowment (click to view images of Mrs. Toppan who lived from 1910-2001). The majority of the materials are printed books, although there are newspapers, magazines, broadsides, illuminated manuscripts, and other materials. Collecting subjects include the American West, British and American Literature, Exploration and Travel, Religion, Hunting and Fishing, historic children's books, and examples of the book arts.
Some books are currently available through an online catalog search, while other books are available through a traditional card catalog located in the Toppan Library. A cataloging project is underway to put more records online.
Toppan Library is directed by one full-time curator, Anne Marie Lane, with several part-time student assistants and volunteers.