pt. I. North Atlantic Coast -- pt. II. South Atlantic Coast and Eastern Gulf of Mexico -- pt. III. Ohio River Basin -- pt. IV. St. Lawrence River Basin -- pt. V. Hudson Bay and Upper Mississippi River -- pt. VI. Missouri River Basin -- pt. VII. Lower Mississippi Basin -- pt. VIII. Western Gulf of Mexico -- pt. IX. Colorado River Basin -- pt. X. The Great Basin -- pt. XI. Pacific Coast in California -- pt. XII. North Pacific Coast