33 C.F.R. § 117.953 – Brazos River (Diversion Channel).

(a) The draw of the S36 highway bridge, mile 4.4 at Freeport, shall open on signal if at least 12 hours notice is given.
(b) The draw of the Union Pacific railroad bridge, mile 22.6 at Brazoria, need not be opened for the passage of vessels.