Keywords: Lock 18 in Great Falls, historical, looking downstream, from HABS.tiff en Lock 18 not Lock 20 in Great Falls MD Although the Library of Congress site where this photo was originally found says Lock 20 close examination of this photo shows it is NOT lock 20 but Lock 18 See file Lock 18 in Great Falls historical detail from HABS tiff for more information - HABS says Caveat not accurate 1 Historic American Buildings Survey John O Brostrup Photographer August 6 1936 10 00 A M VIEW OF LOCKS FROM SOUTHWEST - Chesapeake Ohio Canal Lock No 20 sic MacArthur Boulevard Great Falls Montgomery County MD LOC-image hhh md0875 Historic American Buildings Survey 1936-08-06 MD-19B-1 Chesapeake Ohio Canal National Historical Park |