Great Rivers and Where They End

The Nile runs north for about 6,650 kilometers, formed by the union of the White Nile and Blue Nile at Khartoum. Its predictable annual flood, driven by rains far to the south, deposited the silt that made intensive farming possible along an otherwise arid corridor.

Where the Nile ends, it fans into the Damietta and Rosetta branches and drains into the Mediterranean between Alexandria and Port Said. The delta is densely populated and fertile, with an estimated 70 million people.

The Ganges rises in the Himalayan glaciers of Gangotri and flows roughly 2,525 kilometers across the Indo-Gangetic Plain. Fed by snowmelt and monsoon, its basin supports one of the most densely populated regions on Earth.

The Ganges joins the Brahmaputra and empties into the Bay of Bengal through the world largest river delta, covering more than 105,000 square kilometers across Bangladesh and West Bengal. Its alluvial soils make it one of the most fertile regions on Earth.

The Mississippi rises at Lake Itasca in Minnesota and flows roughly 3,730 kilometers to the Gulf of Mexico. Its drainage basin covers all or part of thirty-two states and two Canadian provinces.

At the Mississippi mouth in southeastern Louisiana, the delta covers roughly 12,000 square kilometers and holds about 37 percent of the estuarine marsh in the continental United States. The river basin draining into it reaches about 41 percent of the contiguous United States.

The Yangtze is the longest river in Asia, about 6,300 kilometers from the Tibetan Plateau to the East China Sea near Shanghai. It divides China roughly into north and south and is dammed at the Three Gorges by the largest hydroelectric station on Earth by installed capacity.

The Danube flows about 2,850 kilometers through ten countries, more than any other river on Earth, before reaching the Black Sea through the Danube Delta in Romania and Ukraine. Vienna, Bratislava, Budapest and Belgrade grew up at its crossings.

The Okavango River does not reach a sea at all. It empties into a tectonic basin in Botswana, and the delta spreads over roughly 6,000 to 15,000 square kilometers by season before nearly all the water is lost to evaporation and plant uptake. UNESCO inscribed it in 2014.

The Colorado River rises in the Rocky Mountains and runs about 2,330 kilometers, carving the Grand Canyon on the way. Damming and diversion for irrigation and cities now leave its lower course dry for most of the year before it reaches the Gulf of California.