Orinoco
History

The mouth of the Orinoco River at the Atlantic Ocean was documented by Christopher Columbus on 1 August 1498, during his third voyage. Its source at the Cerro Delgado–Chalbaud, in the Parima range, was not explored until 453 years later, in 1951. The source, near the Venezuelan– Brazilian border, at 1,047 metres (3,435 ft) above sea level (2°19′05″N 63°21′42″W / 2.31806°N 63.36167°W), was explored in 1951 by a joint French-Venezuelan expedition.

The Orinoco, as well as its tributaries in the eastern llanos such as the Apure and Meta, were explored in the 16th century by German expeditions under Ambrosius Ehinger and his successors. In 1531, starting at the principal outlet in the delta, the Boca de Navios, Diego de Ordaz sailed up the river to the Meta. Antonio de Berrio sailed down the Casanare to the Meta, and then down the Orinoco River and back to Coro. In 1595, after capturing de Berrio to obtain information while conducting an expedition to find the fabled city of El Dorado, the Englishman Sir Walter Raleigh sailed down the river, reaching the savanna country.

Alexander von Humboldt explored the basin in 1800, reporting on the pink river dolphins. He published extensively on the river's flora and fauna.

The sources of the Orinoco River, located at Cerro Carlos Delgado Chalbaud (2º19’05” N, 63º21’42” W), were discovered in 1951 by the French-Venezuelan expedition that went back and explored the Upper Orinoco course to the Sierra Parima near the border with Brazil, headed by Venezuelan army officer Frank Risquez Iribarren.

The first bridge across the Orinoco River, the Angostura Bridge at Ciudad Bolívar, Venezuela, was completed in 1967.

In 1968, an expedition was set off by National Geographic and Hovercraft from Manaus (Brazil) to Port of Spain (Trinidad). Aboard a SR.N6 hovercraft, the expedition members followed the Negro river upstream to where it is joined by the Casiquiare canal, on the border between Colombia and Venezuela. After following the Casiquiare to the Orinoco River they hovered thru perilous rapids of the rivers Maipures and Atures. The Orinoco was then traversed down to its mouths in the Gulf of Paria and then to Port of Spain. The primary purpose of the expedition was filming for the BBC series The World About Us episode "The Last Great Journey on Earth from Amazon to Orinoco by Hovercraft", which aired in 1970, and demonstrated the abilities of a hovercraft, thereby promoting sales of this British invention.

The first powerline crossing of the Orinoco River was completed in 1981 for an 800 kV TL single span of 1,200 metres (3,900 ft) using two towers 110 metres (360 ft) tall.

In 1992, an overhead power line crossing for two 400 kV-circuits was completed just west of Morocure (between the cities of Ciudad Bolívar and Ciudad Guayana), north of the confluence of Routes 1 and 19. It had three towers, and the two spans measured 2,161 metres (7,090 ft) and 2,537 metres (8,323 ft), respectively.

In 2006, a second bridge, known as the Orinoquia Bridge, was completed near Ciudad Guayana, Venezuela.
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