Give them their own land on reservations if they want to practice barbarism and neanderthal culture. Let the land be something they're accustomed to, like the Mojave Desert perpahs. Then let them practice Sharia and we can study them to help understand how mankind lived and survived 1,400 years ago. Maybe Jane Goodall could live amongst them and write another book, "Troglodytes In the Sand".
I think we have some former nuclear testing grounds here in Nevada that might work out....