US lawIllinoisRegulationsTitle 35 — ENVIRONMENTAL PROTECTIONCHAPTER I: POLLUTION CONTROL BOARDSUBCHAPTER a: PERMITS AND GENERAL PROVISIONSPart 204 — PREVENTION OF SIGNIFICANT DETERIORATIONSubpart B204.45035 Ill. Adm. Code 204.450Indian ReservationYear: 2026Length: 21 wordsOfficial source Section 204.450 Indian Reservation "Indian reservation" means any federally recognized reservation established by treaty, agreement, executive order, or Act of Congress.Previous35 Ill. Adm. Code 204.440Next35 Ill. Adm. Code 204.460