Saw a big grackle flock riding my bike so went back at 4pm today and set up with scope. Massive flock was always moving and got several good looks at a Yellow-headed Blackbird in flight with white primary coverts showing well. I conservativley recorded 3,000 grackles. There were a sprinkling of cowbirds and Red-winged Blackbirds mixed in.
The location is the big field at the intersection of Bethany Rd and Stewart Rd. Be careful parking. The birds are moving around the area and have been around a couple of weeks.