33 CFR §117.637

1. (a)The draws of the Maple Street bridge, mile 1.1, and US-31 highway bridge, mile 1.4, both at Manistee, shall operate as follows:
   1. (1)From May 1 through October 31, between 7 a.m. to 11 p.m., the bridges shall open on signal. From 11 p.m. to 7 a.m., the bridges need not open unless notice is given at least two hours in advance of a vessel's time of intended passage through the draws.
   2. (2)From November 1 through April 30, the bridges need not open unless notice is given at least 24 hours in advance of a vessel's time of intended passage through the draws.
2. (b)The CSX Transportation railroad bridge, mile 1.5, at Manistee, shall open on signal from May 1 to October 31. From November 1 to April 30, the bridge need not open unless notice is given at least 24 hours in advance of a vessel's time of intended passage through the draw.