Plains Mill, Historic mill building in Timberville, United States

Plains Mill is a two-story timber-frame building situated along the North Fork Shenandoah River in Rockingham County. The structure features metal siding that now covers its original wooden exterior boards.

The mill was constructed between 1847 and 1849 and operated continuously for nearly 150 years until 1994. During its long working life it processed grains that supported the region's farming communities.

The mill's name comes from the Plains Mill Road address near Timberville, and the site keeps its working layout: the mill building, the 1923 grain bins on the south side and a c. 1959 office building. The mill and office were listed on the National Register of Historic Places in 2014.

The building sits on a private road near Timberville and is visible from the outside, though it remains private property. Daytime visits offer the best light for viewing and photographing this riverside structure.

The mill's power came from a stream that falls over the riverbank directly into the North Fork Shenandoah River beside the building, not from a tributary feeding the river elsewhere. The mill ran on this water power continuously from 1847–1849 until 1994, and a c. 1959 office building on the site was listed with it on the National Register in 2014.