American rivers, lakes and seas, found on the map

Every one on the map

Every place listed below can be asked in this game. Places you find in a passed round drop out of your remaining pool. Grouped into 7 learning regions, matching the rounds on the United States guide. Regions with no places in this map’s selection are omitted. Shared rivers and seas appear in one learning group, even when they cross regional boundaries.

What the map tells you about each one

The paragraph the game shows when you find a place, for all 17 of the ones written by hand. Reading them first is not cheating.

Mississippi

The Mississippi runs about 3,766 kilometers from Lake Itasca in Minnesota to the Gulf, and with the Missouri behind it forms the fourth longest river system in the world. Its basin drains 41 percent of the contiguous United States, water from 31 states and two Canadian provinces. Around 500 million tons of cargo move on it every year.

Missouri

The Missouri is the longest river in North America, about 3,767 kilometers, marginally longer than the Mississippi it flows into. Lewis and Clark went up it in 1804 looking for a water route to the Pacific and found there is not one. Six large dams built between 1937 and 1963 turned its upper half into a chain of reservoirs.

Ohio

The Ohio carries more water than the upper Mississippi does at their meeting point, so by volume it is the main stem and the Mississippi is the tributary. It was the boundary between free and slave states before the Civil War, which is what crossing the river meant to anyone escaping north.

Colorado

The Colorado cut the Grand Canyon, 446 kilometers long and up to 1,800 meters deep, out of rock over some five or six million years. It is now so heavily used that in most years none of it reaches the sea: the 1922 compact that divided the water between seven states was written after an unusually wet decade and allocated more than the river actually carries.

Columbia

The Columbia carries more water than any other river reaching the Pacific from North America, and its fall from the interior plateau to the sea makes it the largest source of hydroelectric power on the continent. Grand Coulee Dam, finished in 1942, is the largest power station in the United States.

Rio Grande

The Rio Grande is the border for about 2,020 kilometers, from El Paso to the Gulf, and the shifting of its channel used to move the border with it until a 1970 treaty fixed the line. Mexico calls it the Río Bravo del Norte. So much is taken out for irrigation that stretches of it run dry most years.

Snake

The Snake cut Hells Canyon on the Idaho and Oregon line, which at about 2,400 meters is deeper than the Grand Canyon, though far narrower and less visited. Its plain is a sheet of basalt laid down by the same hotspot that now sits under Yellowstone, which the North American plate has been sliding westward over for sixteen million years.

Lake Superior

Superior holds about 12,100 cubic kilometers of water, more than the other four Great Lakes together, and by surface area is the largest freshwater lake in the world at 82,100 square kilometers. It is cold enough and deep enough that things sunk in it do not surface: the Edmund Fitzgerald went down here in a November storm in 1975 with all twenty-nine aboard.

Lake Erie

Erie averages only 19 meters deep, which makes it the warmest and the most easily fouled of the five. The Cuyahoga River running into it at Cleveland caught fire in 1969, one of at least a dozen times it had done so, and the photographs helped push the Clean Water Act through Congress in 1972.

Great Salt Lake

Great Salt Lake has no outlet, so everything that runs in stays and only the water evaporates, leaving it several times saltier than the ocean. It is what remains of Lake Bonneville, which covered much of Utah in the last ice age. Its level swings enormously with the weather, and it has fallen to record lows through the last decade.

Lake Mead

Lake Mead is the largest reservoir in the country by capacity and is held by Hoover Dam, finished in 1936 and 221 meters high. It supplies water to Las Vegas, Los Angeles and Phoenix, and the pale band of mineral on the rock above the waterline, the bathtub ring, marks how far it has dropped since 2000.

Lake Tahoe

Tahoe is 501 meters deep, the second deepest lake in the country after Crater Lake, and sits at 1,897 meters in the Sierra Nevada. It is famously clear: a white disk lowered into it stays visible to around 20 meters, though that has declined from about 30 meters when measurements began in 1968.

Lake Okeechobee

Okeechobee covers about 1,900 square kilometers and averages under three meters deep, which is why a hurricane can push it out of its bed. In 1928 one drove the water over the southern shore and killed at least 2,500 people. The dike built afterwards cut off the flow that fed the Everglades below it.

Salton Sea

The Salton Sea is an accident. In 1905 an irrigation cut from the Colorado failed and the whole river poured into a dry basin below sea level for eighteen months before engineers closed it. Nothing flows out, so it has been getting saltier ever since, and as it shrinks the exposed lakebed blows dust across the valley.

Chesapeake Bay

The Chesapeake is the largest estuary in the country, about 320 kilometers long, and is the drowned lower valley of the Susquehanna, flooded when the sea rose after the last ice age. Its oyster beds once filtered the whole volume of the bay in a few days; the population is a small fraction of what it was in the 1880s.

Gulf of Mexico

The Gulf covers about 1.6 million square kilometers and is warm enough to be the engine of the hurricanes that cross it. The Loop Current running through it feeds the Gulf Stream out past Florida. The Deepwater Horizon rig failed here in April 2010 and released some 780 million liters of oil over eighty-seven days.

Salish Sea

The Salish Sea is the name given since 1988 to the whole system of Puget Sound, the Strait of Juan de Fuca and the Strait of Georgia, which the border runs through and which had no single name before. It is named for the Coast Salish peoples, and it holds one of the last resident populations of killer whales in the region.

How this one works

The other maps of the United States

Sweden has the same map in Swedish waters. Denmark has the same map in Danish waters. India has the same map in Indian waters. Mexico has the same map in Mexican waters. China has the same map in Chinese waters. Turkey has the same map in Turkish waters. France has the same map in French waters. Japan has the same map in Japanese waters. Germany has the same map in German waters. Spain has the same map in Spanish waters. Brazil has the same map in Brazilian waters. United Kingdom has the same map in British waters. Italy has the same map in Italian waters. South Korea has the same map in Korean waters. All three together on the United States atlas page, the country itself on the United States guide, and the other two hundred on the world map.