The Austin H. Merrill Papers consist of correspondence, reports, diagrams, and photographs (some with accompanying negatives) related to mines and mining in Shasta County, Butte County, Mexico, Alaska, Oregon, and Nevada. Contained within the collection is information pertaining to the following mines: Yankee John Mine, Milkmaid Mine, Washington Mine, French Gulch, American Mine, Silver King Mine, Niagara Summit, Riverside Mine (Alaska), Golden Treasure Mine (Mexico), Rainbow Mine (Oregon), and Goldfield (Nevada).

Many of the reports include geological surveys and assessments of the mines, which consist of estimates and recommendations for development, operation, and cost. Some of the reports include drawings or diagrams illustrating mining developments and operations, such as the six diagrams depicting the mine shafts of Yankee John Mine. Also included in the collection is an owner’s statement for the Silver King Mine by L. C. Parker, dated March 9, 1915, a handwritten history of the Yankee John Mine by John F. Reese, dated January 3, 1939, Assay Certificates by James A. Leslie, a record of accounts from the Washington Mine October 14, 1937 through February 18, 1938, and mining claims from French Gulch, including Halcyon Gold Quartz Claim, Midway Gold Quartz Mine, Ruby Pearl Quartz Mine, Lone Pine Gold Quartz Mine, and Globe Gold Quartz Mine. The photographs contained within the collection were taken of several different mines, including Yankee John Mine, Milkmaid Mine, Washington Mine, French Gulch, American Mine, French Gulch, Riverside Mine, Golden Treasure Mine, Rainbow Mine, and Goldfield.

Besides Austin H. Merrill there are other names included in some of the correspondence and reports, such as Richard L. Smith, W. L. Clark, W. Y. Humphreys, W. L. Hill, J. H. Scott, John F. Reese, L. T. Pockman, John A. Kruse, Lutellus Smith, W. M. Johnston, and H. A. Houser. Also included are Assay Certificates by James A. Leslie.