The Eureka Consolidated Mining Company was an underground, hard rock mining company operating about two miles from Eureka, Nevada on Ruby Hill. The collection includes mining reports, correspondence, maps, and technical drawings which documents structures, head frames, underground facilities, mining equipment, and the Ruby Hill Water Company. One group of records relates to a 1950s proposal to bring a nuclear power plant to Eureka.

The Richmond-Eureka Mining Company was a mining company located at Ruby Hill, Nevada. The collection includes minutes and bylaws of the Richmond Mining Company, 1873-1906; land and mineral rights patents, 1872-1880; reports and assay reports; misc. correspondence; financial materials; maps; photographs; and text of Thomas Wren's argument in the court case of Richmond Mining Company of Nevada vs. Eureka Mining Company, 1881.

Ruby Hill Development Company was a development and mining company in Eureka, Nevada. Included are engineers' reports for the Ruby Hill mining property two miles west of Eureka, Nevada, providing a history of the mine between 1919-1936, and maps and evaluation of future prospects; correspondence and notes about the Richmond-Eureka Mining Company and the U.S. Smelting and Refining Company.