Section 117.553 - Choptank River(a) The draw of the Maryland 331 bridge, mile 35.3, at Dover, shall open on signal from 6 a.m. to 6 p.m., year-round, and the draw shall remain closed from 6 p.m. to 6 a.m., year-round, unless 24 hours advance notice is given by calling (301) 820-8592 or (301) 745-2096.(b) The draw of the Conrail bridge, mile 50.9 at Denton, shall open on signal from May 30 through September 30 from sunrise to sunset and at all other times if at least four hours notice is given.CGD 82-025, 49 FR 17452, Apr. 24, 1984, as amended by CGD5-90-059, 55 FR 35622, Aug. 31, 1990