Chronology of Events in the Land Dispute

1882 President Chester A. Arthur issues an executive order reserving 2.5 million acres around the Hopi Mesas for the Hopi and "such other Indians as the Secretary of the Interior may see fit to settle thereon."
1891 Navajo-Hopi Boundary conflicts are reported to have been brought to "a satisfatory conclusion" with the establishment of a 519,000 acre area for the Hopis.
1936-43 Grazing District 6 is set aside for Hopi use; subsequent expansion from 384,000 to 650, 013 acres forces the first relocation of Navajo families.
1958 Congress passes legislation authorizing a lawsuit to determine ownership of the 1882 Reservation.
1962 A special three-judge federal court rules that 1.8 million acres of the 1882 Reservation are owned jointly by the two tribes. This area becomes known as the Joint Use Area (JUA). A year later the Supreme Court summarily affirms the decision.
1972 The district court in Arizona orders drastic Navajo livestock reduction to allow for Hopi use of half the JUA range; the order also bars construction in the JUA.
1974 Congress passes the Navajo-Hopi Land Settlement Act, providing for equal partition of the JUA and the relocation of members of one tribe living on the land partitioned to the other.
1977 The U.S. District Court of Arizona divides the former Joint Use Area into the Navajo Partitioned Lands (NPL) and the Hopi Partitioned Lands (HPL).
1980 Congress passes Public Law 96-305, an amendment to 93-531.
1985 Morris-Clark Mission
1988 First Amendment Suit

From The Second Long Walk and The Wind Won't Know Me