Ruddy ducks are more of a western duck and are not very common in the eastern part of the US. The same is true for the state of Minnesota. Ruddy ducks are much more common in the western part of the state.
I have taken some good pics of ruddy ducks out in Montana but these were the best ones that I have been able to get in Minnesota. This past weekend I visited the park at the Coon Rapids Damn in the northern part of the Twin Cities. While there I saw another group of ruddy ducks, but they were further away and much more difficult to shoot the way that they usually are for me in Minnesota.