Where was the Fort located?
Fort Roberdeau was located within Sinking Spring Valley Manor, an area now known as Tyrone Township, Blair County, Pennsylvania. The term manor was applied to the most valuable properties in Pennsylvania that the descendants of William Penn, the founder of the Commonwealth, wished to retain for themselves. Sinking Valley contained fertile farmland as well as deposits of important metal ores, namely lead, zinc, nickel and iron. The valley was also well watered, even if the streams did disappear underground.
During the American Revolution, 1775-1781, Bedford County, Pennsylvania was much larger than it is today. It included much of the drainage area of the three upper tributaries of the Juniata River (the Little Juniata, the Frankstown Branch, and the Raystown Branch), and extended south to the Pennsylvania-Maryland border. Fort Roberdeau was located in the northern part of this large county.