We're located in Minneapolis, MN and the photos were taken today (May27). Based on my limited knowledge of trees and my searching on the interwebs, I've come to the weak conclusion that we have Honey Locust Tree in our backyard. Are you a tree expert or know more than I do? Then comment on the type of tree we have. And if I know you, I owe you beer / drink the next time I see you.
According to my friend Adrian (see comments for links), this is a black locust tree due the size of the seed pods.