After building the St. Jean Block next door in 1893, Dr. Felix St. Jean again hired respected Anaconda mason John Cosgrove to build this annex building in 1897. Cosgrove, an old friend of Marcus Daly’s, also built the foundations of the Upper Works of the Anaconda Company smelter and many prominent masonry buildings on Main Street and East Park Avenue. The original storefront housed Dr. St. Jean’s Standard Drug Company until 1900 when optician and jeweler L. F. Verbeckmoes moved in. Other early twentieth-century upstairs tenants included Mabel Smith’s Embroidery Shop, the John Hillberg Photo Studio, and Anaconda’s first chiropractor, Dr. R. D. Sawtell. In 1903, wealthy Billings mercantile owners Christian and Peter Yegen opened the Yegen Bros. Savings Bank here, later incorporating as the National Bank of Anaconda in 1905. In 1915, the Yegen brothers added an exuberant Neoclassical façade featuring fluted stone columns with Ionic capitals, tall divided-light transom windows, a polished terra-cotta tile entablature with the bank name, and a stately copper paneled door surround. It remains one of Anaconda’s best examples of Neoclassical design.