In Chicago I always know that it's the end of summer when two things happen:
1) my allergies kick in and start driving me crazy
2) they raise all the bridges over the Chicago River and let the boats head for their winter storage.
I figured that you'd rather have footage of #2 than #1... here are the bridges being raised and the boats passing at Randolph and then later at Lake Street. The Lake Street bridge is interesting because the "L" rides on top of that bridge, as well (the Red and Blue lines go under the river, the Brown and Green lines go on the overhead tracks).