My son and I have both done some fishing on the Lemont section of the DesPlaines.  The most common fish in the river are cat and carp but there is a occasional northern and some crappie. From Willow Springs Road to a couple of miles down stream of Lemont the river banks are mostly undeveloped and slow enough current it can be paddled both directions. It can be a nice place to paddle after dark when you may see deer and coyotes.
MagicPaddler