1. Potomac Case study

2. Potomac River Basin Thelin and Pike 1991, USGS Map I-2206

3. Potomac Basin - 1905 Rivers of North America: A Reading Lesson for Students of Geography and Geology, by Israel C. Russell, New York, G.P.Putnam’s Sons London, John Murray 1905

5. Hancock, Washington County, MD Map – Microsoft MapPoint

6. Westernport MD Map – Microsoft MapPoint

7. Alexandria VA Map – Microsoft MapPoint

8. Loudoun County VA Map – Microsoft MapPoint

9. Shenandoah and Rockingham Counties VA Map – Microsoft MapPoint

10. Prince Williams County VA Map – Microsoft MapPoint

11. http://www.potomacriver.org/

12. http://www.fergusonfoundation.org/cleanupfacts.html

13. Watershed photo

14. Scarps (Issues map)

15. Bay Crater

16. Subsidence

17. Rivers - Crater

18. Low Sea Level