33 CFR § 117.391 - Chicago River.
The draws of the bridges operated by the City of Chicago over the Main Branch of Chicago River, the bridges on the North Branch of Chicago River from the Main Branch to North Halsted Street, mile 2.65, and bridges on the South Branch of Chicago River from the Main Branch to South Ashland Avenue, mile 4.47, shall operate as follows:
(a) For commercial vessels, all bridges shall open on signal if at least 12-hours advance notice is provided to the Chicago City Bridge Desk prior to the intended time of passage; except that, from Monday through Friday between the hours of 7 a.m. and 9:30 a.m., and between the hours of 4 p.m. and 6:30 p.m., except for Federal holidays, the draws need not open for the passage of vessels.
(b) For recreational vessels:
(1) From April 1 through November 30 -
(i) The draws shall be scheduled to open, before 1 p.m., twice on Saturdays and twice on Sundays if requests for passage have been received at least 20 hours in advance. If the bridges have been authorized to remain closed for portions of a Saturday or Sunday to accommodate special events, openings shall be scheduled after 1 p.m. as necessary to provide two openings per day.
(ii) The draws shall open on Monday and Friday, after 6:30 p.m. Each opening requires notice that has been given at least 6 hours in advance of a vessel's requested time of passage.
(iii) The draws shall open on Wednesdays at 10 a.m., or as soon thereafter as practical, if a request for passage has been given at least 20 hours in advance.
(iv) The draws shall open at times in addition to those listed in paragraphs (b)(1)(i) through (b)(1)(iii) of this section, after notice has been given at least 20 hours in advance requesting passage for a flotilla of at least five vessels. However, the bridges need not open Monday through Friday from 7 a.m. to 9:30 a.m., and 4 p.m. to 6:30 p.m., except for Federal holidays.
(2) From December 1 through March 31, the draws shall open on signal if at least 48 hours notice is given. However, the bridges need not open Monday through Friday from 7 a.m. to 9:30 a.m., and 4 p.m. to 6:30 p.m., except for Federal holidays.
(c) The following bridges need not be opened for the passage of vessels: The draws of South Damen Avenue, mile 6.14, over South Branch of Chicago River; all highway drawbridges between South Western Avenue, mile 6.7, and Willow Springs Road, mile 19.4, over Chicago Sanitary and Ship Canal; North Halsted Street, mile 2.85, and Division Street, mile 2.99, over North Branch Canal of Chicago River; and Division Street, mile 3.30, North Avenue, mile 3.81, Cortland Avenue, mile 4.48, Webster Avenue, mile 4.85, North Ashland Avenue, mile 4.90, and Union Pacific Railroad, mile 5.01, over North Branch of Chicago River.
(d) The draw of the Chicago Avenue Bridge, mile 2.40, over the North Branch of the Chicago River, need not open for the passage of vessels.
(e) The Amtrak Bridge, mile 3.77, is authorized to operate remotely and open to the intermediate position on signal, unless a request for a full opening is received by the drawtender. The bridge is required to operate a marine radio.