I found a Northern Mockingbird this morning, 22 May 2015 at 8:00 am, on my regular bird walk around Commonwealth Terrace Cooperative (student and family housing, on the south end of the University of Minnesota, St. Paul campus) and adjacent Sarita Wetland. The bird was present at the tennis courts, which are east of Fifield Street and north of Gibbs Avenue on the property, which is owned by the University of Minnesota. The tennis courts are not visible from roads, so if you want to try for the bird, I suggest looking up Commonwealth Terrace Cooperative on Google Maps to see the layout of roads and sidewalks within the property (the tennis courts are easy to see in aerial imagery, located southwest of the Google Maps marker for Commonwealth Terrace Cooperative), parking along Como Avenue just to the south (free streetside parking), and walking to the tennis courts area. When I left the bird, it was in the tree at the southwest corner of the courts.
Falcon Heights, MN