Thanks for the tip - I'm in SD right now on vacation and was having trouble finding RR Sours. Clems had Supplication, Consecratation, and Temptation in stock. They were $15 a bottle, but I got 2 of each to take back to NC with me. No Pliny though.
I also hit Alpine Brewing, since my brother lives a few miles from Alpine and I was in the area. Their kriek is amazing, and I tried their Duet IPA too and I was good. It's not a fancy place, but the beer and food are great and the staff is very friendly. It's worth a stop if you don't mind a 30 minute trip east to the foothills.
The Best Damn Bottle shop is good too, but they only had Supplication for RR sours. The selection of other craft brews was excellent.