The Chicago Tribune has their nearly annual story about bald eagles today.
As winter set in in the upper midwest, the bald eagles are moving south, especially to the locks and dams on the Mississippi River between Dubuque and Quincy, which one Army Corps of Engineers spokesman has described as being fish buffets. Other places with lots of sightings are along the Illinois River, especially near Starved Rock State Park, but the Fox, Rock and DuPage rivers are also good viewing places.
Here in Nebraska I've seen dozens of bald eagles along the Big Blue river near Fairbury, but I suspect the Platte has them as well, and probably the Missouri, too.
In 1963 there were 417 known nesting pairs of bald eagles in the lower 48 states. The population is now estimated to be over 316,700.