Keefe-Mumbower Mill, also recorded as the Evans-Mumbower Mill, is a preserved grist mill on Wissahickon Creek in Upper Gwynedd Township, Pennsylvania. Built in 1835, the 3½-story banked stucco-over-stone mill later received a two-story wood-frame reproduction addition. It operated until 1930 and contained an Oliver Evans milling system, the automated technology that reshaped American flour milling in the early 19th century. Because it survives as an actual working creek-side mill rather than a rebuilt replica, it is an important part of the Wissahickon valley’s industrial history. Now owned by the Wissahickon Valley Watershed Association, it functions as a museum with monthly public tours and demonstrations.