Norwegian immigrant Tom Toston established a ranch and ferry near here in 1871, and because the site stood at the junction of the Helena-Gallatin Valley Road and the road to Radersburg, a settlement quickly grew around his ranch. The town soon had a post office, mercantile, hotel, and a smelter that processed ore from the Radersburg mines. A bridge replaced Toston’s ferry in the 1890s, but by the 1910s it had become unsafe, leading local residents to petition the Broadwater County commissioners for a replacement. In 1918, State Highway Department engineer Charles A. Kyle developed a riveted steel Warren through truss design for this Missouri River crossing, a form valued for low cost, durability, and its trademark W-shaped trusses. In July 1919, county commissioners awarded the contract to the Billings-based Security Bridge Company, which used eleven men on the project, many of them local, including longtime Toston resident William Lorentz. Lorentz, a Pennsylvania native, had come to Toston in 1884 to work for the Northern Pacific Railway, was a carpenter by trade, served as the last superintendent of the Toston smelter, and helped build bridges for the Montana Railroad Company. Completed in July 1920, the Toston Bridge became an integral part of the community because it lay on the highway between Helena and Bozeman, and during the 1920s teenage girls would parade across it on summer evenings for lack of something better to do. The highway bypassed Toston and the bridge in 1955.