The fall bridge lift season begins Saturday in Chicago, a sign that summer is coming to a close. All moveable bridges along the south and main branches of the Chicago River will be raised to allow boats to make their way from harbors in Lake Michigan to their winter storage units.

The bridge raising Saturday starts at 9:30 AM sharp, and according to spokesman Brian Steele for the Chicago Department of Transportation, they may draw a crowd. He said depending on the weather, dozens of people have been known to show up to watch the bridge raising. The order the bridges move follows the same sequence each year.

“We start at Lake Shore Drive, head west on the main branch and then turn south on the south branch of the Chicago River. we have three or four different crews that hopscotch each other  and open the next bridge in line—so lake shore drive is first, columbus is second, michigan avenue is third, and so on and so forth,” he said.

Steele said there shouldn’t be any traffic delays as the bridges are usually only raised for about 8 to 12 minutes. Bridge lift season lasts through mid-November. The bridges will be raised in the same fashion on Saturdays and Wednesdays throughout the season, at 9:30 and 9:00 AM respectively.