1. Short title This Act may be cited as the Casa Grande Ruins National Monument Boundary Modification Act of 2019 . 2. Findings Congress finds that— (1) Casa Grande Ruin Reservation was— (A) set aside on March 2, 1889; (B) proclaimed as the first archaeological preserve in the United States on June 22, 1892; and (C) redesignated as the Casa Grande Ruins National Monument on August 3, 1918; (2) the Casa Grande Ruins National Monument protects 1 of the finest architectural examples of 13th century Hohokam culture in the Southwest, which was known to early Spanish explorers as the Great House ; (3) Casa Grande is only part of the story of an ancient town that may have covered 2 square miles