Section 117.671 - Upper Mississippi River(a) The draws of all bridges between Lock and Dam No. 14, mile 493.3, and Lock and Dam No. 2, mile 815.2, shall open on signal; except that, from on or about December 15 through the last day of February, the draws shall open on signal if at least 24 hours notice is given.(b) The draws of all bridges between Lock and Dam No. 2, mile 815.2 and Lock and Dam No. 1, mile 847.6, shall open on signal; except that, from on or about December 15 through the last day of February, the draws shall open on signal if at least 12 hours notice is given.USCG-2016-0561, 82 FR 55322 , Nov. 21, 2017