The 1867 edition of the Pacific Coast Business Directory lists King, Webb & Co. as engaging in assaying and banking in Idaho. Around the same time King, Myrick & Co. (successors to E. W. Tracy) was listed as doing business in Silver City, Idaho Territory, and being composed of Mark A. King and Edward Webb (located in Silver City) and Josiah Myrick (located in Portland, Oregon). The 1871-1873 edition of the Pacific Coast Business Directory lists Mark A. King as an assayer in Portland, Oregon. An 1868 prospectus of the War Eagle Mountain Tunnel Company, Owyhee District, Idaho Territory, listed Webb and Myrick as persons, among others, who could attest to the character of the person who wrote the prospectus.