The King Arthur Flour Company operates an excellent store for bakers near their headquarters in Norwich, VT.  In addition to pastry flour and bread flour and rye flour, they sell a variety of specialty flours, including some milled in the French, Italian, Irish, and other styles.

In addition to the flour that one might expect to find at a flour store, they carry the most astonishing array of other bakers' supplies! All  sorts of thing you might not expect to find in a retail establishment, like "everything". Everything is what's on top of an Everything Bagel, of course - that odd and oddly universal mix of poppy seeds, sesame seeds, kosher salt and what have you.

Aside from great ingredients, they have a great assortment of baking pans, gadgets, and other useful stuff for the serious baker.

But wait - there's more! They practice what they preach, so they have a bakery counter with some delectables, and good coffee. They also have a cooler with some local cheeses, but you're better going to Hanover for local cheeses. 

Norwich is about 5 miles north of Quechee Gorge, where I-89 crosses from New Hampshire into Vermont. It is also directly across the river from Hanover, home to the excellent Hanover Food Coop, so we typically visit both places in the same trip.