According to Oregon Pub 17, page 59, if you are an American Indian you might not have to pay Oregon income tax on all or part of your income. You may be able to subtract all or part of your income if all of the following are true:
"Indian country" is defined as any land within a current federal Indian reservation boundary and other lands held in trust by the United States government for a tribe.
If you meet the above qualifications then exempt income includes the following:
To claim this subtraction you must file Form OR-EIS, Exempt Income Schedule for Enrolled Members of a Federally recognized American Indian Tribe with your Oregon return. You can get this form at the following address on the DOR website: http://www.oregon.gov/DOR/forms/FormsPubs/exempt-income-schedule-federal-american-tribe_101-687.pdf
To enter the American Indian Income Subtraction in TaxAct: