Contains 36 Yellowstone National Park black and white stereographs, with a few duplicates of varying quality. The dates range from 1871 to 1910. The stereographs were produced by several photographers, the main contributors being Joshua Crissman, Henry Bird Calfee, and the Nelson (Nelse) partnership.

Contains records of Robert Edgar Collet, Jr. Includes a family group sheet with their information and dates on their children. Also includes a collection of postcards from Yellowstone, and a few photographs. Dated 1914-2009.

Typewritten report with photographs glued into a photo album with the report. The item was addressed to Horace M. Albright, superintendant of Yellowstone National Park. Gregg informs Albright about the exploration of the Bechler River district on the Yellowstone.

Collection contains files and records used in the creation of the Yellowstone bibliography. Most of these files are citations and reference lists found by A. Dean Larsen during his research. Much of the research focused on the history of Yellowstone, its wildlife and forest preservation, and personal accounts of the park. Materials dated 1998 to 2005.

Handwritten diary in pencil with a transcription in ink by Barry D. Johnson, one of Ellerman's grandsons. Ellerman writes about the campaign against the Dakota Indians from June to September in 1873 by the Seventh Cavalry of the United States Army. Several pages of the diary are missing.

Reminiscenes of living in the Park as a child and his father's work as superintendent of road construction in the Park for Morrison-Knudsen Company.