Tribal gaming revenues in the U.S. may exceed those of the 12 leading commercial gambling states according to industry experts.

Frank Fahrenkopf, the president and Chief Executive Officer of the American Gaming Association said that just last year, tribal gambling brought in more than $26 billion while commercial gambling revenue totaled $34 billion.

Tribal casino revenues may continue to increase by more than $1 billion a year.

Tribal casinos profit reports are confidential, but Nevada gambling experts estimate that Thunder Valley takes in $500 million – $600 million annually.

A tribal spokesman said that the Auburn Indians have become one of the most generous philanthropic organizations in northern California, donating $1 million to Sutter Auburn Faith Hospital.