The Oliver G. Traphagen House, also known as Redstone, is a historic residential building in Duluth, Minnesota, United States. Built in 1892 as a duplex, it was designed and inhabited by architect Oliver G. Traphagen (1854–1932). The building was listed on the National Register of Historic Places in 1975 for its local significance in the theme of architecture. It was nominated for its association with Traphagen, recognized together with his business partner Francis W. Fitzpatrick as Duluth's leading architects of the late 19th century.

Francis Willford Fitzpatrick was an architect in Duluth, Minnesota, Washington, DC, Omaha, Nebraska, and Evanston, Illinois. He often abbreviated his name as F. W. Fitzpatrick in publications and correspondence. Fitzpatrick was an early advocate of fireproof buildings, and he was a frequent columnist in architectural trade publications on a variety of topics.