There is a county boat launch on north side of the St. Joe river in South Bend, IN. Look for Keller Park and this boat launch with a large parking lot is just 0.3 miles before it with proper signage.
I have been birding from past 5 years or so, but never got such a wonderful chance to shoot this duck from so near! We live next to a river where lots of waterbirds overwinter and spend lot of time in unfrozen waters. Sunny days in Midwestern winters tend to be unusually chilly and also provides the best chance to shoot these dainty ducks with good light that highlights its amazing iridescent plumage. After many unsuccessful trials to be near them what I noticed is there is a sharp bend in the river with lots of small trees and also noticed that these are diving ducks and have a special tendency to be near this bend. I used their diving to get close gradually and unnoticed till I was almost with 5-10 ft of them and whenever they emerged out of the water it provided me a wonderful chance to capture their amazing beauty and the sun at right was helpful indeed.