A little off the beaten path in Tulsa (12th & Peoria), you'll find the This Land Store. Inside the shop, I have a carefully curated selection of locally-themed art prints (including a Route 66 art print that is available exclusively at TLS). They've put together a great shop full of books, art and clothing.
Even if you're not local, This Land Press publishes many great works. They're progressive and fiercely independent and deserve support.