Subject to the provisions of sections
640d–8 and
640d–16
(a) of this title, any lands partitioned to the Navajo Tribe pursuant to sections
640d–2 and
640d–3 of this title and the lands described in the Act of June 14, 1934 (
48 Stat. 960), except the lands as described in section
640d–7 of this title, shall be held in trust by the United States exclusively for the Navajo Tribe and as a part of the Navajo Reservation.