Larger subsidiaries and affiliates Bunker Hill included Caledonia Mines, Kellogg, Idaho; Metaline Contact Mines in northeastern Washington; Pend Oreille Mines and Metals Co., Metaline Falls, Washington; and Reeves MacDonald Mines, Ltd., Salmo B.C.

The Caledonia Mining Company was incorporated July 1, 1907, with Stanly Easton as its president and manager. it had 2 patented claims in the Yreka district adjacent to Bunker Hill claims, in fact, the equipment to work the mine was rented from Bunker Hill which also controlled a majority of the stock. During the depression of 1921 Caledonia managed to maintain capacity production, but closed the latter part of 1927 except for unimportant leasing operations. The records for this company include financial ledgers and journals, cashbooks, voucher registers, stock and dividend records, most covering the years 1907-1918.

Metaline Falls Lead and Zinc (1928-1931) was reorganized as Metaline Metals (1931-1945), and later became Metaline Contact Mines (1949-1952). Records for these companies include minute books, 1928-1945, a financial journal, 1928-1944, and audit reports, 1949-1952.

Pend Oreille Lead and Zinc was taken over by Pend Oreille Mines and Metals in 1929, and in 1945 Metaline Metals merged with the company. Pend Oreille Mines and Metals merged into Bunker Hill in 1974. Pend Oreille Oil and Gas was a wholly owned subsidiary of Pend Oreille Mines and Metals. The records for the Pend Oreille Mines were originally in two large storage boxes. They were transferred to smaller (l cubic foot) boxes during processing, but the original order and folder headings were retained. Among the records are articles of incorporation, minute books, annual reports, correspondence, alphabetical filed maintained by Don Wilson, secretary of the company, which include financial records, correspondence and dividend records.

Reeves MacDonald Mines, Ltd, of Salmo/Remac B.C. was owned 60% by Pend Oreille Mines. It was developed with Spokane capital in 1949. The main Reeves mine worked out in 1970, but later work was carried out in the Annex mine on the other side of the Pend Oreille River. Mining operations discontinued about October 1, 1973, although development and exploration continued until all operations shut down in March 1975. In 1974 the British Columbia government passed a new Mining Tax Law which greatly increased the royalties paid to the provincial government. This act was protested by mining companies, but in September 1976 Reeves MacDonald and the other B.C. mining companies dropped their appeal. In September 1977 the plant and equipment were sold at public auction. Records relating to this mine are similar to those of the Pend Oreille mine since Don Wilson was secretary for both companies.

The Sierra Nevada Consolidated Mining Company, located in the Yreka District, Shoshone County, Idaho, was incorporated in November 1886, under the laws of the State of Oregon. During the years 1920-1922 the company acquired certain mining properties consisting of approximately 114 acres formerly owned by Coeur d'Alene Development Co. In August 1926, the company sold the surface rights to these properties to the Sullivan Mining Co. for $5,000. Mining operations by the company were discontinued in the year 1923, but subsequent to that date portions of the properties were operated by lessees on a royalty basis. Records for this company span the years 1914 to 1943 and include a financial journal, audit report, and bullion record.

Smaller affiliates include North American Mining & Milling Co., North Idaho Phosphate Co., Northwest Lead Co., Sullivan Mining Co., Treadwell Yukon, and Zinc Lock, which each contain only a few items. The records for all the affiliates are arranged alphabetically by mine name.