Raystown Lake is an 8,300-acre man-made impoundment of the Raystown Branch of the Juniata River. The dam, completed in 1973, backs up water for over 30 miles. Raystown Dam is operated by the United States Army Corps of Engineers as a flood control dam protecting populated areas from flooding from Huntingdon, Pennsylvania to the mouth of the Susquehanna River as it flows into the Chesapeake Bay. Raystown Dam has saved property owners and municipalities tens of millions of dollars in flood damage that would have occurred since construction was started in 1971.