Dpeends on location usually. On Native American reservations, usually very Democratic, at least 70% or more. In Oklahoma, where the largest population of them reside all over the state not always on reservations, there's evidence they could be voting majority Republican. Overall: Usually Democratic, 60%+
But low turnout is consistent in these areas.
The GOP can pull those numbers? That's quite impressive actually. The Canadian Tories are happy to pull 10% on reserve and they're not nearly as right wing as the GOP.