Sandy is correct as there are only 4 screwpile lighthouses remaining on the Chesapeake Bay, all in MD. and only one still active, Thomas Point Shoal. Paul is correct as a number of websites indicate that there were 42 built in the Chesapeake Bay. Laura, you might be interested in the link below which is a National Park Service Maritime Heritage Program page with some screwpile information that mentions that "Perhaps as many as 100 spider-like, cottage-type (1½-story wooden dwelling) screwpile lighthouses were built throughout the Carolina sounds, the Chesapeake Bay, Delaware Bay, along the Gulf of Mexico, at least two in Long Island Sound and one even at Maumee Bay (1855), Lake Erie, Ohio. Few survive to this day; many were replaced with caisson-type lighthouses."


http://www.nps.gov/history/maritime/constype/screw.htm

I'll leave it up to Sandy or Paul, whichever has a question ready to go.


mg