(Above) Michigan Avenue Bridge on August 25, 2008, from Wacker Drive, looking northeast. Tribune Tower in background. Click on image to view larger version.

April 29, 2010 – Friends of the Chicago River, an organization that runs a museum in its southwest tower, is planning a birthday party in May for the Michigan Avenue Bridge.

The 399-foot-long double-deck bascule bridge opened on May 14, 1920 after three years of construction. It was designed by Edward H. Bennett (1874-1954) who co-authored with Daniel Burnham the 1909 Plan of Chicago. When it opened, the bridge was the main link between downtown Chicago and the north side.

The McCormick Bridgehouse and Chicago River Museum, which will open for its fifth season, is planning a free preview on May 14. Cake will be served at 10:30 a.m. to the first 90 guests.

“The bridge opened to much fanfare on May 14, 1920,” reads a press release from Friends of the Chicago River. “Its groundbreaking design and engineering continue to inspire awe today.”

In the spring and fall, visitors to the museum can watch as gears raise and lower the bridge.