PSA (Palametto State Armory) bought NoDak Spud a couple years ago. The Ruger American Ranch sights have not been made since then. PSA is supposedly going to put them back in production. There is a 3 page thread about it on AR15 dot com about it. PSA was replying to questions there. no recent update. But if you google 'NoDak Spud Ruger American Ranch Iron Sights' it should be the first thing that comes up, you can read about it there.
I'd really like a set for myself