I just returned from that area (part of a 5000 mile trip through southern Canada & northern US). At both the Lode Star & Golden Buffalo, the cage was willing to sell me chips even though the tables were not open (we arrived there in the morning).

You need to add the Rosebud (often referred to as being in Mission, SD, but actually way down by the Neb. border on US 83) to the list. BTW: The Prairie Winds is a nice new facility with a hotel. It is on the Pine Ridge Reservation but is located about half way between Oglala & Oelrichs.

There are a lot of other "casinos" in SD & Montana adversing along the roadsides. They are all little (5-10 machine) joints without table games.

I will be publishing scans of my haul (about 10 POUNDS of chips) when I get caught up a little.