Anyone from or who traveled through central MN (Mille Lacs area) in the 80's remember "Bach's" gun-shop? I grew up in central ND. Every summer we'd travel to central MN to spend a week with college friends of my parents. Dad and I would always take 1 day and hit up gun-shops around Mille Lacs. I couldn't tell you how to get there, I just remember a building in a meadow surrounded by trees. Wood floors and the whole bit. In connection w/JB's gun-shop story, I can remember my dad buying one of those Colt 22 revolvers @ Bach's.
Bach's is long-gone. Reed's in Walker MN now only has consignment used firearms, no more trading. "The Corner Store" in Backus, MN is small, maybe 100ish guns, but, he does a brisk business in used guns, turns inventory regularly, and almost always has something interesting on the shelf. The owner fancies SxS shotguns and there are usually 20-30 great specimens. From Win 21's through Savage/Stevens 311's, guild guns, all kinds of stuff. Throw in the odd Pre-64 M70 and some used late-model shotguns, I try to find time to stop anytime I'm within 50Mi or so.
Another gunshop that "loonies" who get nearby need to budget time for is Boone's Fine Guns about an 60-90min NW of Minneapolis in Isle MN on the SE corner of Lake Mille Lacs. Sakos, Kimbers, Savage 99's, Winchester 70's, 60 series takedowns, 66's, 73's, 86's, Remington, Ruger, and Browning collectables, yes, plurals. He's got a set of Winchester roller skates in the box, along with a supply-ship rope-launching gun in it's original box. Thousands, if not 10's of thousands of collectable ammo boxes. No wood floor, but, I promise, you won't miss it. The good and bad about Boone's is they have a crappy website which means you just have to go there.
Shooting Sports just E of Little Falls, MN is a "must stop". There are a couple of Pawn Shops in Bemidji MN that have interesting guns at times.
BrotherHood Arms in Watertown SD has a really good mix of AR/Tactical stuff as well as wood/blued and a very well-stocked reloading dept. Sodak Sports in Aberdeen and Mitchell are also worth making time for if you're close.
Of Course 1st Stop in Rapid City also deserves a mention. I'm told there's a basement, I've yet to be invited down there for a look.......
