Applications must be filed online.
The closing date is August 8.
Preference will be given to persons of Indian descent who are:
(a) Members of any recognized Indian tribe now under Federal jurisdiction;
(b) Descendants of such members who were, on June 1, 1934, residing within the present boundaries of any Indian reservation;
(c) All others of one-half or more Indian blood of tribes indigenous to the U.S., and
(d) Eskimos and other aboriginal people in Alaska,” according to 25CFR 5.1.
You can read more about the position here.