Railroad Creek Valley was first explored in some detail by an engineering party in the employ of the Great Northern Railway seeking a passage across the Cascade Mountains in 1887. One of the "engineers" was J. H. Holden, a member of the surveying party. He made note of an iron-stained ore body on the side of Copper Mountain almost 1000 feet above Railroad Creek. After the Great Northern Railroad decided not to use Railroad Valley, Mr. Holden returned to the valley to develop the ore body he had previously observed. But his venture was doomed to failure for lack of funds by the end of World War I in 1918. Very little happened until 1928 when Brittany Mining and Smelting leased the property to explore the ore deposit. In 1937, the Howe Sound Company built the concentrating plant, the mill, the docks on Lake Chelan, and the living accommodations for the miners. In addition, they built roads, and a 54-mile power line to bring in electricity for the mill operation.