Sharing this link - good cold zones only apple pollinations chart
Those of you up here in zone 4 know it can be frustrating looking for good reference materials focused of stuff we can ACTUALLY grow.
I have been doing a lot of research on fruit trees and pollination. The other day I was at Menards and saw some nice apple trees, but of course the tree labelling wasn't great so I went home and googled the nursery on the label. Guess what!! - They had a great catalog and even better cold weather only pollination charts. Perfect. I found a good chart with varieties missing from most other charts - even the look up at Orange Pippin.
So I thought I would share. I hope others find this helpful.