Good question, as I understand it tribal land is sovereign nation, the royalty are paid by the oil production companies. It a version of what happens federally with the tribes being beneficiaries of payments.

The only difference is some of the tribes divide said gains and pay royalties to tribal members directly, after of course taking administration fees.

Occasionally I read of infrastructure and or educational investments, but more so the tribal gambling band wagon. Arguably a higher return on investment, (and revenge on the white man).

Some look beyond, and build with conversations of manufacturing in mind.