This series contains maps (ca. 1950 – 1978) issued chiefly by the U.S. Army Corps of Engineers–Tulsa District, the Bureau of Indian Affairs, and allied federal agencies, ranging in size from letter-format reconnaissance maps to large-scale blueprints. Together they document tribal trust lands, school construction, water and flood-control projects, navigable streams, soil surveys, and selected international conflict and tourism maps—offering a snapshot of mid-20th-century land-use planning, resource management, and geopolitical concerns centered on Oklahoma and the Arkansas–Red River basin yet extending from the Persian Gulf to Vietnam.