The draws of the bridges, except for the Atchison Railroad Bridge, Mile 422.5, see § 117.411(b) for further details, across the Missouri River shall open on signal; except during the winter season between the date of closure and date of opening of the commercial navigation season as published by the Army Corps of Engineers, the draws need not open unless at least 24-hours advance notice is given.
33 C.F.R. §117.687