U.S. Physical FeaturesOnline version U.S. Map by Blake Metzger 1 Smokey Mountains 2 Piedmont 3 Cape Cod 4 Appalachian Mountains 5 Great Salt Lake 6 Cascade Mountains 7 Massachusetts Bay 8 Great Plains 9 Sierra Mountains 10 Chesapeake Bay 11 Pacific Ocean 12 Atlantic Ocean 13 Gulf of Mexico 14 Cumberland Gap 15 Lake Champlain 16 Lake Superior 17 Lake Michigan 18 ST. Lawrence River 19 Columbia River 20 Rio Grande 21 Lake Huron 22 Wabash River 23 Lake Ontario 24 Lake Ontario 25 Lake Eerie 26 James River 27 Mississippi River 28 Hudson River 29 Missouri River 30 Potomac River