The world's great rivers are full of surprises. These stories run from a blind fish that revealed the deepest river on Earth to a Mississippi control structure designed with help from Einstein's son, and from an explorer who paddled to the wrong ocean to an elephant sent to test a bridge. Along the way you will meet guides, engineers, a folk singer and a record-breaking stingray.
Every tile in a Great Rivers game carries one of these. Open one to read it now, or leave them for the board to hand you.
Rivers
nine stories
1The blind fish that revealed a river's depth
On the tile: Congo2008
Scientists studying the lower Congo River kept finding a pale, blind cichlid that looked like a cave fish, though the river has no caves. It turned up only dying or dead. Melanie Stiassny of the American Museum of Natural History found the clue in one barely alive fish: it had the bends, like a diver who surfaces too fast. Powerful currents were shooting fish up from the depths. In 2008 the museum and the U.S. Geological Survey measured the river at least 220 meters (over 700 feet) deep, the deepest river known.
Since the 1930s, schoolchildren have learned that the Rhine is 1,320 kilometers long. In 2010 biologist Bruno Kremer, writing about the river's ecology, realized the number was wrong. Reference books from 1903, 1907 and 1909 had all given 1,230 kilometers. Then the Knaurs lexicon of 1932 swapped two digits, the Brockhaus of 1933 copied the mistake, and it was accepted ever since. The international commission for the hydrology of the Rhine basin now gives the official length as 1,232.7 kilometers, about 90 fewer than the famous figure.
The Danube passes through 10 countries and four national capitals on its way to the Black Sea. But in southwestern Germany, between Immendingen and Fridingen, the young river leaks into the limestone beneath it. At the main sinkhole near Immendingen, up to 8 cubic meters of water a second can vanish, and in some years the riverbed there is dry for almost 200 days. Three days later that water reappears at the Aach spring, then flows through Lake Constance and down the Rhine to the North Sea.
China's Yellow River is named for the fine loess sediment it carries toward the sea, and that load is also its danger. On the North China Plain, sediment settles on the riverbed and builds it up, so in many places the river lies above the surrounding land, held in by levees. North of the city of Kaifeng, its low-water level is about 15 feet above the countryside, and in high water it can stand 30 to 35 feet above the land. It has changed course across the plain several times, earning names like China's Sorrow.
East of Manaus, Brazil, two great rivers meet and then flow side by side in the same channel for several kilometers without blending. The Rio Negro is nearly free of sediment and stained the color of black tea by decayed leaves and plants. The Rio Solimões is coffee-colored, rich with sediment washed down from the Andes. The Solimões is also cooler, denser and faster, and the boundary between them is visible even from space. Eventually turbulent eddies stir the two together, and they merge to become the lower Amazon.
Between December 1811 and February 1812, three earthquakes of roughly magnitude 7 to 7.5 struck along the Mississippi. They are named for New Madrid, a Missouri river town the last one destroyed. The first woke people as far away as New York City and Washington, D.C. On the river, flatboat operators reported that the Mississippi suddenly reversed its flow. Scientists now think the tremors sent waves moving northward, giving the illusion that the river ran backward. The shaking also reshaped the land: in Tennessee, ground sank and filled with water to create Reelfoot Lake.
The Colorado River is supposed to end in the Sea of Cortez, between mainland Mexico and Baja California, but for years its water had not reached it. In March 2014, under a U.S.-Mexico agreement called Minute 319, about 105,000 acre-feet of water were released through Morelos Dam as an experiment. Most soaked into the ground within the first 37 miles. Even so, on May 15, 2014, the river reached the sea for the first time in more than a decade, and satellites later measured a 43 percent increase in green vegetation along its path.
The Okavango River runs about 1,500 kilometers but never reaches the ocean. In northwestern Botswana it fans out into the Okavango Delta, one of very few large inland deltas with no outlet to the sea; its water drains instead into the desert sands of the Kalahari. Oddly, its yearly flood arrives during the dry season, and the delta's plants and animals have timed their lives to match. The delta is also the core area for Botswana's elephants, the largest elephant population in the world at around 130,000.
For part of the year, Cambodia's great lake, the Tonle Sap, drains southeast toward the Mekong through a river of its own. Then the monsoon arrives. From about June to November, the swollen Mekong reverses that river's flow and pushes water back into the lake. The lake's area grows from about 1,050 square miles to about 4,000, and its depth from 3 to 10 feet to as much as 30 to 45 feet. The largest body of fresh water in Southeast Asia, it supports a big fishing industry and many floating fishing villages.
In 1541 Francisco de Orellana was second in command of Gonzalo Pizarro's expedition east of Quito. With food running out, Pizarro sent him downstream in December 1541 in a brigantine with 57 men to look for supplies. Swift currents carried them so far that returning to Pizarro seemed impossible, so they drifted on. In August 1542 they reached the river's mouth. Back in Spain, Orellana told of meeting tribes led by women, like the Amazons of Greek myth, a comparison presumed to have given the river its name.
At the Battle of Shiloh in 1862, a bullet shattered John Wesley Powell's right forearm, and surgeons amputated the shattered part. Seven years later, on May 24, 1869, he set out from Green River Station, Wyoming, with four small boats and ran the Green and Colorado rivers through the Grand Canyon, a trip many had thought impossible. As director of the U.S. Geological Survey from 1881 to 1894, he advocated water conservation in the West. “There is not enough water to irrigate all the lands,” he told a congress of farmers and developers in 1893.
In 1858, returning from Lake Tanganyika with Richard Burton, John Hanning Speke struck out north alone and became the first European to reach the vast lake he named for Queen Victoria. He declared it a source of the Nile. Burton rejected the claim, and many in England doubted it. Speke went back, and on July 28, 1862, found where the Nile leaves the lake, naming the spot Ripon Falls. In 1864, on the day the rivals were to debate it in public, Speke was killed by his own gun while hunting. He had been right.
In 1795 the African Association backed a Scottish surgeon, Mungo Park, to explore the true course of the Niger River. Held prisoner for four months, he escaped on July 1, 1796, with little more than a horse and a compass, and later that month reached the Niger at Ségou, in today's Mali. He was the first European to establish that it flowed east, and his book was a popular success. On a second expedition he went far down the river, but he drowned after an attack at the Bussa rapids in about 1806.
In 1832 an Ojibwe guide named Ozaawindib led Henry Rowe Schoolcraft's expedition to the head of the Mississippi, a lake the Ojibwe called Omashkoozo-Zaaga'igan, Elk Lake. Schoolcraft renamed it using the Latin words veritas (truth) and caput (head): Itasca, the true source. Back at Cass Lake, he gave Ozaawindib a medal, a sign that the United States recognized Ozaawindib as a chief. Today visitors at Itasca State Park wade across the infant Mississippi where it leaves the lake, in water about 18 inches deep, and Ozawindib Lake in the park honors the guide.
The Roosevelt-Rondon Scientific Expedition of 1913 and 1914 followed the River of Doubt through the Brazilian Amazon. Former President Theodore Roosevelt's partner was Cândido Rondon, a Brazilian officer who had spent years building telegraph lines in the region and in 1910 became director of Brazil's new Indian Protection Service. Rondon's motto was “die, if necessary, but do not kill.” The journey brought Roosevelt within days of death, and the river was renamed the Rio Roosevelt. Rondon lived to 92 and is one of Brazil's most cherished national figures.
In 1789 fur trader Alexander Mackenzie left Fort Chipewyan to test a theory that a great westward river led to the Pacific. After an arduous canoe trip of about 2,500 kilometers, the river he followed, which the Dene call Deh Cho, or Big River, emptied into the Arctic Ocean instead: a colossal dead end. It now bears his name. Four years later he reached the Pacific overland and wrote on a rock, in vermilion mixed with melted grease, “Alexander Mackenzie, from Canada, by land, the twenty-second of July, one thousand seven hundred and ninety-three.”
Mary Kingsley never went to school; she read her way through her father's library, especially its travel and science books. After a first trip to West Africa in 1893, she returned in 1894, sailed up the Ogooué River in Gabon and climbed Mount Cameroon, an active volcano. She brought home insects, shells, plants, 18 species of reptiles and 65 species of fish. Three of the fish were new to scientists in England and were named for her, among them Ctenopoma kingsleyae. Her books, including Travels in West Africa, argued for greater understanding of African cultures.
In May 1541 Hernando de Soto's army reached the Mississippi River, and in June it crossed into what is now Arkansas. De Soto had convinced local peoples that he was an immortal “Son of the Sun,” so when he died of a fever near the river in May 1542, his men hid his death. They buried him in secret, then weighted his body and sank it in the Mississippi. The survivors built boats, floated down to the sea and reached Mexico in 1543. In 1855 a painting of his discovery went up in the U.S. Capitol Rotunda.
The Amazon flows through Peru, Colombia and Brazil, and more than 30 million people live in its basin, yet no bridge crosses the river. Much of it winds through sparsely populated country with few major roads for a bridge to connect. In the dry season it averages 2 to 6 miles wide; in the wet season it can spread to 30 miles, with water 50 feet higher, and its soft banks erode and shift. River towns rely on boats and ferries instead. Near Manaus, a bridge opened in 2011 spans a tributary, the Rio Negro.
As James B. Eads's bridge across the Mississippi at St. Louis neared completion in 1874, many people doubted it was safe. Folklore of the time held that an elephant could sense unsafe ground and would refuse to cross it. So on June 14, 1874, a test elephant was led onto the span, and it walked from the St. Louis side to Illinois without incident. Eads then had 14 locomotives drive back and forth over the bridge. It opened on July 4, 1874, and still carries traffic across the Mississippi today.
Visitors to Hoover Dam often ask how many workers are buried in its concrete. The Bureau of Reclamation's answer is none. The dam was built as interlocking blocks, each five feet high, filled by buckets carrying eight cubic yards of concrete at a time. Each bucketful raised the level only two to six inches, and crews called puddlers stamped and vibrated it into place to remove air pockets. Reclamation's official count of fatalities in building the dam is 96, men lost to drowning, blasting, falls and other accidents.
After the 2004 Sumatra earthquake, NASA scientists calculated that it had shortened Earth's day by 2.68 microseconds. To explain how shifting mass changes the planet's spin, geophysicist Benjamin Fong Chao compared it with China's Three Gorges reservoir. Filled, the reservoir would hold 40 cubic kilometers (10 trillion gallons) of water. Raising that much water would lengthen the day by 0.06 microseconds, make Earth very slightly rounder in the middle and flatter on top, and move the pole about two centimeters. Even the earthquake's effect was too small to detect, though it could be calculated.
When Egypt decided to build the Aswan High Dam, its reservoir threatened to flood the valley holding the temples of Ramses II at Abu Simbel. In 1959, after an appeal from Egypt and Sudan, UNESCO launched an international rescue campaign. Workers cut the colossal statues by hand, moved the temples in blocks weighing 20 to 30 tons, and reassembled them on higher ground under an artificial hill. The relocated temples were inaugurated in September 1968. The campaign cost about $80 million, half of it donated by some 50 countries, and it helped inspire the 1972 World Heritage Convention.
In May 1941 the Bonneville Power Administration, a four-year-old federal agency, hired folk singer Woody Guthrie to write songs for a film about public power and the dams on the Columbia River. In thirty days he wrote twenty-six songs, including “Roll On, Columbia,” “The Grand Coulee Dam” and “Pastures of Plenty.” He was paid $266.66, which the agency's information officer, Stephen Kahn, called one of the best bargains the U.S. government ever got. In 1987 the lyrics to all twenty-six were recovered, and “Roll On, Columbia” is now Washington's official folk song.
A popular tale says the American who bought London Bridge in 1968 thought he was getting the far grander Tower Bridge. Not so, says Lake Havasu City: Robert P. McCulloch knew exactly which bridge he was buying. It was John Rennie's granite bridge, opened across the Thames in 1831, which was sinking about an inch every eight years under the weight of motor traffic. Its 10,276 exterior granite blocks were numbered, shipped through the Panama Canal and trucked to Arizona. The rebuilt bridge was dedicated on October 10, 1971, over a channel dredged beneath it.
8The engineers' ring that was not made from a bridge
On the tile: Iron Ring1907Myth busted
Many Canadian engineers wear a plain ring on the little finger of their working hand. A popular belief holds that the first rings were made from the debris of a bridge collapse. The tradition does trace back to a disaster: in 1907 the Quebec Bridge fell into the St. Lawrence River during construction, and 75 of the 86 workers on it died. But the original rings were made of iron by patients at a veterans' hospital in Toronto. Rudyard Kipling wrote the ceremony, first held in 1925, and most rings today are stainless steel.
Budapest's Chain Bridge was the first permanent crossing of the Danube in the city. English engineer William Tierney Clark designed it, and a Scottish engineer who shared his surname, 28-year-old Adam Clark, directed the construction, which began in 1839. In May 1849, during the siege of Buda, imperial troops tried to blow up the bridge. Adam Clark saved it by flooding the chain chambers, and it opened to the public on November 20, 1849. Clark settled in Hungary for good, and in 1899 the bridge was named for the reformer István Széchenyi.
Samuel Clemens, a former Mississippi riverboat pilot, began signing his work Mark Twain in 1863. On the river, “mark twain” meant water two fathoms, or 12 feet, deep. Clemens later claimed he took the name from an old captain, Isaiah Sellers, after Sellers died. But Sellers signed his river reports “I. Sellers,” and he died a year after Clemens adopted the name. A Nevada newspaper said it came from his saloon tab instead, and a book dealer has since found “Mark Twain” in an 1861 humor magazine. Scholars still generally favor the riverboat call.
In Egypt, the size of the Nile's yearly flood decided the harvest, and so it decided taxes. On Roda Island in Cairo stands a nilometer built in 861 by order of the Abbasid caliph al-Mutawakkil: a well around an octagonal marble pillar marked in cubits. Taxes on farmland were calculated from the size of each year's flood, and levied only once the water reached a designated level. The idea was far older; archaeologists say nilometers set taxes in the time of the pharaohs. The yearly floods ended with the Aswan High Dam in 1970.
In February 1814 the Thames froze between London Bridge and Blackfriars, and Londoners threw a raucous five-day fair on the ice. It had a main street signposted the City Road, swings for children and close to a dozen printing presses churning out souvenir poems. One printer, George Davis, published a 124-page book, Frostiana, from his stall on the ice. Eyewitnesses even reported an elephant being led across near Blackfriars Bridge. It was the last frost fair. The medieval London Bridge, whose closely spaced piers helped ice dam the river, was replaced in 1831.
On the night of June 13, 2022, a fisher from Koh Preah island, on the Mekong in northern Cambodia, hooked a giant freshwater stingray and alerted the Wonders of the Mekong research team. Scientists confirmed a weight of 661 pounds (300 kilograms) and a length of more than 13 feet, making it the largest freshwater fish on record. It beat a 646-pound Mekong giant catfish caught in Thailand in 2005. The female was fitted with an acoustic tag and released. Fishers named her Boramy, meaning full moon, for the moon rising as she swam off.
The baiji was a dolphin found only in China, in the Yangtze River system and the neighboring Qiantang River. There may have been thousands in the 1950s, but by the 1980s surveys estimated just 400. The poor-sighted dolphins drowned in fishing gear and collided with ever more ships. A male named QiQi lived 22 years in a dolphinarium in Wuhan and died in 2002, the same year a photograph gave the last confirmed evidence of a wild baiji. In 2006 scientists searched the Yangtze for six weeks and found none. The baiji is thought to be the first cetacean driven extinct by humans.
The giant water lily of the Amazon basin was named for Britain's new queen, Victoria, after the explorer Robert Schomburgk sent specimens to London from British Guiana in 1837. In 1849 Joseph Paxton, the Duke of Devonshire's gardener, raised one at Chatsworth in a specially built tank, and on November 14 its first flower opened. Paxton carried a flower and leaf to the Queen. To show off the leaves, which grew up to five feet across, he stood his young daughter Annie on one. Ribs beneath the leaf keep it sturdy, and they helped inspire his Crystal Palace.
In the hot summer of 1858, sewage in the Thames made London smell so bad that the season became known as the Great Stink. Anyone who could afford to left the city, and curtains and blinds were soaked in chloride of lime to block the odor. Parliament was sitting, and lawmakers felt the full force of it: outside their windows, waste baked on the exposed riverbeds. A bill proposed by Benjamin Disraeli to fund a new sewer became law in just 18 days. Engineer Joseph Bazalgette's brick-lined tunnels still form the basis of London's sewers.
In March 1800 the naturalist Alexander von Humboldt watched fishermen in South America drive about 30 horses and mules into a pool full of electric eels. The eels rose from the mud and attacked, and in his account two horses were stunned and drowned within five minutes. For 200 years no scientist reported anything similar, and some suspected he had exaggerated. Then Vanderbilt biologist Kenneth Catania saw cornered eels leap from the water, press their chins against a threatening net and fire high-voltage pulses. In 2016 he concluded that Humboldt had probably seen the same thing. Leaping may help defend eels confined to ponds in the Amazon basin's dry season.
Each summer, Chinook salmon enter the mouth of the Yukon River in Alaska and swim upstream toward spawning grounds in Canada's Yukon Territory, some traveling more than 2,000 river miles. Fish that enter in mid-May reach the Canadian border about two months later. Near Whitehorse they pass a hydroelectric dam by climbing what Yukon Energy calls the longest wooden fish ladder in the world, where a camera now counts them. Scientists are tracking tagged fish from the river's mouth to learn why some fail to finish the journey; heat stress and disease are leading suspects.