I like their flour too, but I didn’t know they have mugs!
On one of my parents trips north they stopped in a Wheat Montana deli (not sure which one). Mom got the 4 mugs and gave them to me and she got 4 big cereal bowls for herself.
I just did a little searching and found you can order their flour products from the one in Kalispell, MT. They also have a gift shop but can't see how to order things from the shop.