Henry Trapp

• Geology and ground-water resources of Hettinger and Stark Counties, North Dakota
• Ground water basic data, Hettinger and Stark Counties, North Dakota
• Hydrogeologic framework of the northern Atlantic Coastal Plain in parts of North Carolina, Virginia, Maryland, Delaware, New Jersey, and New York
• Test well DO-CE 88 at Cambridge, Dorchester County, Maryland
• The regional aquifer system underlying the northern Atlantic Coastal Plain in parts of North Carolina, Virginia, Maryland, Delaware, New Jersey, and New York
• Three-dimensional steady-state simulation of flow in the sand-and-gravel aquifer, southern Escambia County, Florida
• Water resources of Okaloosa County and adjacent areas, Florida