SAGINAW RIVER REAR RANGE LIGHTHOUSE-ESSEXVILLE, MICHIGAN

                                                                                                Aerial view of Saginaw Coast Guard Station circa 1965
                                                                                                       Photograph courtesy of Archives of Michigan

                                                                                               Rear Range Light In 1904
                                                                                  Photograph Courtesy of  National Archives

LUDINGTON NORTH PIERHEAD LIGHTHOUSE-LUDINGTON, MICHIGAN

                                                                                  BREAKWATER LIGHTHOUSE IN 1935
                                                                     PHOTOGRAPH COURTESY OF U.S. COAST GUARD

MUSKEGON SOUTH BREAKWATER LIGHTHOUSE-MUSKEGON, MICHIGAN

                                                                                                Aerial view of Muskegon Harbor showing various lights.
                                                                                                         Photograph courtesy Archives of Michigan

MUSKEGON SOUTH PIERHEAD LIGHT-MUSKEGON, MICHIGAN

CHICAGO HARBOR LIGHTHOUSE-CHICAGO, ILLINOIS

CHICAGO HARBOR SOUTHEAST GUIDEWALL LIGHTHOUSE-CHICAGO, ILLINOIS

To comply with a 1930 Supreme Court order that limited the amount of water allowed to flow from Lake Michigan into the Chicago River, a set of locks was built at the river’s entrance between 1936 and 1938. It was at this time that the Chicago Harbor Southeast Guidewall was built, and the present tower was established at its eastern end in 1938. The Sanitary District of Chicago awarded a construction contract for the lock and guidewalls to the Frazier-Davis Construction Company. The lock and appurtenant structures were built under a War Department permit to prevent the reversal of the river into the lake during periods of heavy rains. The Chicago River was reversed in 1900 to flow into the Sanitary and Ship Canal and then eventually into the Mississippi River. This reversal separated the city’s Lake Michigan drinking water supply from the sewage effluent in the Chicago River and helped prevent cholera/typhoid epidemics. The Southeast Guidewall Light was described in 1938 as "a white steel tower, the upper part of which is inclosed, surmounted by a fourth order vertical bar lantern housing the lens. The light is occulting, showing a white light of 6,600 c.p., 1 seconds in duration every 2 seconds. The fog bell is mounted on a bracket attached to the lake side of the tower and sounds a single stroked at 10-second intervals." Also in 1938, a light was established on the west end of the south guidewall and on the east end of the north guide wall. These two additional aids were thirty-one-foot-tall skeleton steel towers. The north guidewall tower was painted a straw color and showed a flashing red light while the inner south guidewall tower was white and exhibited a flashing white light. The Chicago Harbor Lock opens around 10,000 times each year, making it the second busiest lock in the country. Over 50,000 vessels, carrying around 900,000 passengers, pass through the lock annually.