Geology of the Chesapeake and Ohio Canal National Historical Park and Potomac River Corridor District of Columbia Maryland West Virginia and Virginia: USGS Open-File Report 2001-01-188b

The United States Geological Survey (USGS) is a scientific organization created in 1879 and is part of the U.S. government. Their scientists explore our environment and ecosystems to determine the natural dangers we are facing. The agency has over 10000 employees that collect monitor and analyze data so that they have a better understanding of our problems. The USGS is dedicated to provide reliable investigated information to enhance and protect our quality of life. This is one of their circulars.