The Lyman S. Willardson photograph collection consists of 13,798 slides, prints, and negatives. These images document his research in agriculture and irrigation as well as his travels. Included are irrigation projects and water experiments throughout the United States including Montana, Wyoming, Nebraska, California, Colorado, Utah, New Mexico, Arizona, Ohio, Indiana, North Dakota, Idaho and Washington, and overseas in Egypt. Also included are images of presentations, charts and graphs, lab equipment and machinery, and laboratory experiments.