Each of the four bridge houses of the Michigan Avenue Bridge are adorned by limestone bas-relief sculptures commemorating important events in Chicago's history. Sculpted by James Earl Fraser, best known for his representation of Native Americans, they were added in 1928.
Pictured here, on the northeast pylon, is the 11-foot, 10-inch wide "The Discoverers". The relief portrays French explorers Louis Joliet and Jacques Marquette, who determined in 1678 that Chicago was the site of the passage between the Great Lakes and the Mississippi River system; and Rene Robert Cavelier-Sieur de La Salle, and his lieutenant, Henri de Tonti, who explored the entire Mississippi River area between 1679 and 1682. Although Marquette was a Jesuit priest, he is depicted in the robes of a Franciscan monk. There is a profile of a kneeling indian in the foreground. An allegorical female figure floats above the more boldly carved, Beaux-Arts figure group.
Below the relief, on the pylon reads the following inscription:
The Discoverers, Joliet, Father Marquette, LaSalle and Tonti will live in American history as fearless explorers who made their way through the Great Lakes and across this watershed to the Mississippi in the late seventeenth century and typify the spirit of brave adventure, which has always been firmly planted in the character of the middle west. Presented to the City by William Wrigley Jr., 1928.
The Michigan Avenue Bridge, which links the Loop with the Magnificent Mile, was built in 1920. It was the first double-deck bascule bridge ever built. Spanning the Chicago River, the bridges two leaves, each weighing 3340 tons, open by turning on enormous trunnion bearings on the riverbanks. The Michigan Avenue Bridge is one of 20 downtown bridges spanning the Chicago River, in a city that has the greatest number of movable bridges in the world.
The Michigan Avenue Bridge and Esplanade was designated a landmark by the Chicago Department of Planning and Development on October 2, 1991.