Alvah Washington Townley Farmstead Historic District, also known as Osage County Museum, is a historic farm and national historic district located at Chamois, Osage County, Missouri. It encompasses five contributing buildings. They are the two-story, frame I-house (c. 1856) with modest Greek Revival styling; a smokehouse (c. 1875); multipurpose barn (c. 1872); wood and machine shed (c. 1874); and a combination poultry house, outhouse, and storage shed (c. 1870). The property was deeded it to the Osage County Historical Society, who operate it as a museum.
It was listed on the National Register of Historic Places in 2003.