The C&O Canal National Historical Park is in a constantly shifting, dynamic state. Weather and climate change, geologic processes, flooding and human-caused factors such as air and water pollution are only a few of the agents of change that have helped to carve the Potomac River Valley. The park provides a "living laboratory" that helps us better understand how these environmental factors have shaped park landscapes and ecosystems. Park staff carefully monitor changes in environmental factors, and can often alert managers to threats to the resources in time to preserve those resources.