Originally Posted by geomorph
Yes it looks like it is a river in Milwaukee now that I see the map, one that is largely channelized in that stretch that I visited. It looks like there are a few short canals or channels just south of where the river turns East toward the lake?
milwaukee is home to 3 rivers (milwaukee river, menomonee river, and kinnickinnic river) that flow together to form the estuary that serves as milwaukee's harbor. the menomonee river stretches west from downtown milwaukee as it flows through the menomonee valley. the menomonee valley was formely a very swampy tangle of braided streams, ponds, and marshes. in the late 19th century much of it was channelized and drained to open up land for industrial purposes. so those dead end channels that you see southwest of downtown milwaukee that look like canals are actually just channelized remnants of the old menomonee valley waterways.
most of the natural rivers in milwaukee have been heavily dredged, widened, straightened, and channelized back when they were serious "working" rivers, so it can be easy to confuse them for canals today, but they're all based on original natural rivers. rivers like these that have been highly manipulated to serve the needs of man definitely can blur the distinction between a man-made canal and a natural river.