Mapping a Mythical River

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by Joe Gelt and Melissa L. Lamberton

Maps do more than record geography; maps also reflect myths and human longings. Consider the mapping of the Buenaveventura River.

The Buenaventura River was once thought to flow from the Rocky Mountains to the Pacific Ocean over what is now the western United States. Such a river was much sought with several candidates identified before the Buenaventura River. Explorers were seeking the Great River of the West that would be the western segment of a coast-to-coast waterway, an easy route for travel and trade. Coloring these explorations was the dream of a Northwest Passage. A map by Robert Sayer (1750?) has the Great River of the West flowing from Lake Winnipeg.

Historian Bernard DeVoto wrote of the Great River of the West: “It must exist because it had to. The logic of deduction from known things required it to, and so did the syllogism of dream — both on no grounds whatever.”

Settlers facing the vast expanse between the Rockies and the Sierra Nevada believed fervently in this riverine mirage. John Melish in 1816 and Albert Finley in 1826 (See Finley map at right) both drew maps displaying the Buenaventura connecting the Great Salt Lake with the Bay of San Francisco. John Robinson’s 1819 map shows no less than three rivers flowing to the Pacific.

The myth was laid to rest by Explorer John Fremont who regretfully concluded at the end of his journey that the Buenaventura never existed. He had difficulty convincing President Polk that so many official maps were wrong.

Consider also case of California, shown on many old maps as an island. Its actual attachment to the mainland, the next-door neighbor to Arizona, has been the cause of many interstate conflicts, the most acrimonious having to do with water. Many Arizona officials, no doubt, have longingly reflected on those old maps that display a California Island.

In a much different cartographic category is the Water Resources Research Center’s water map. Despite Arizona’s longing for additional water resources the map provides no mythical water body that would offer the state a new water source. Instead, accuracy is stressed, both cartographically and hydrologically. (See insert after page 6 to learn about the new WRRC water map.)