Morning Ed, that is a nice dollar token. South Dakota. Casino opened in 1990 and closed in 1991

Token facts:
.999 Fine Silver, not Sterling
Should weigh in at .85 Troy Weight
Should be coin aligned
Should have a fully reeded rim
And I do see the NCM Mint

This design was also made in nickel so since it does not say silver or sterling on it the best way to know is to either have it tested or go off the weight. If silver them .85 but if nickel then around .70 in weight

As for a value, I would say $50 - $80 ******
And this is just my opinion, some collectors would never spend $50 and others would jump at the chance to spend $80 to fill a hole in their collections