The small settlement along Sam’s Creek near the border between Carroll and Frederick counties is an intact survivor of a once common nineteenth-century development pattern in the grain-growing areas of Maryland. The McKinstry family owned an earlier gristmill on the site, which they replaced in 1844 with the current three-and-a-half-story rubble stone and frame building. Miller Samuel McKinstry built his own center-hall house nearby in 1849. The grouping also includes the McKinstry homestead (c. 1825; 4504 Sam’s Creek Road), a combination store and dwelling (1850; 1494 McKinstrys Mill), two other small houses, and a variety of associated outbuildings for domestic and agricultural purposes. McKinstry proudly included marble datestones with his initials on the mill, house, and store. Also noteworthy is a Warren pony-truss steel bridge that spans Sam’s Creek. It was fabricated in 1908 by the York Bridge Company in York, Pennsylvania, and is the only surviving metal truss bridge in Carroll County.