The non-existent Buenaventura River, alternatively San Buenaventura River, Río Buenaventura, etc. was once believed to run from the Rocky Mountains to the Pacific Ocean in what is now the western United States. The river was chronologically the last of several imagined incarnations of an imagined Great River of the West which would be for North America west of the Rockies what the Mississippi River was east of the Rockies. The hopes were to find a waterway from coast to coast, sparing the traveling around Cape Horn at the tip of South America.[1]
In 1776, two Franciscan missionaries Francisco Atanasio Domínguez and Silvestre Vélez de Escalante sought to find a land route between Santa Fe in New Mexico to Monterey in California. (Both of these states were then Spanish provinces.) They were part of a ten man expedition under the military leadership of Bernardo Miera y Pacheco. (They were joined en route by two Native American guides.)[2] On September 13, they encountered what is now called the Green River, a southward-flowing tributary of the Colorado and named it San Buenaventura after the catholic saint Bonaventure.
At that point in time, there was nothing mythical about the Buenaventura River. Escalante’s journal[3] correctly notes that above their crossing, the river flowed toward the west. It flowed generally southwest where they crossed it and continued southwest as they traveled in its vicinity. Escalante also correctly recorded that after its junction with the Rio San Clemente (today’s White River? – which he also named) the Buenaventura River turned to the south.[4] So, the original Buenaventura River is real and exists today under a different name.
After establishing contact with a branch of the Ute (Yutahs) Tribe on the south shore of what is now called Utah Lake (then Lake Timpanogos – various spellings), the expedition turned south-southwest. On September 29, they were surprised to come upon a river flowing from the south-southwest and turning at the point they encountered it toward the west. Escalante noted in his journal that the Native American name for this river suggested it was the same river he had named Buenaventura. He also noted that they concluded it was not the same river and listed his reasons why. He named this river the Rio San Ysabel. The Native Americans told them it flowed west from there into a lake (Sevier Lake) and beyond. The Rio San Ysabel is known today as the Sevier River.
One can only guess why the map produced by Miera equates the Buenaventura with the Ysabel. Perhaps he believed his military position gave him not only the authority but also the superior judgment to reject Escalante’s conclusion and adopt the identity of these two rivers suggested by the Native American name. (Note that the Native Americans did not say the two rivers were the same.) In any case, his map showed the Buenaventura River flowing southwest and into a lake bearing his name. In an accompanying note to king Charles III of Spain Miera recommended building several missions in the area and mentioned the possibility of a water way to the Pacific Ocean, via the Buenaventura or the Timpanogos River.
The error of representing the Buenaventura River as flowing southwest was but the first in a series of errors by other cartographers. [5] There had long been a hope that a river flowing west from the Rocky Mountains to the Pacific Ocean would provide an easy route for travel and trade. This dream was the descendant of the long sought Northwest Passage. (A map by Robert Sayer (1750?)[6] shows the Great River of the West flowing from Lake Winnipeg.)
A map by J. Finlayson (1822) shows a Rio de S. Buenaventura originating near the “Principle [sic] source of the Rio Colorado” and emptying into a salt lake the western limits of which “are unknown”. This same map indicates that an uncharted Rio de San Filipe crosses a range of mountains at 122 degrees west longitude. A map by Sidney E Morse (1825) similarly shows the Rio de San Buenaventura flowing into a lake, the western limits of which are unknown. This map shows an unnamed river extending east from San Francisco Bay toward this lake, but not connecting with it. A map by Thomas Bradford (1835) shows a river flowing to San Francisco Bay (mislabeled Sir Francis Drake) from the south end of Lake Timpanogos. There is no reference to Rio de San Buenaventura. A map by Albert Gallatin (1836) labels the current Sacramento River as the Buenaventura and equates Lake Timpanogos with Great Salt Lake. A map by H.S. Tanner (1836) applies the name Buenaventura to what is now the Salinas River of California, flowing north toward Monterey Bay. An 1844 map by James Bowden shows a landlocked Buenaventura wrapping around the southeast side of a “doubtful” Lake Timpanogos. Henry S. Tanner’s influential map of 1822 shows the Buenaventura River flowing from the north central Rockies through a salt lake to a non-existent bay in the neighborhood of Cape San Martin.[7] This map also shows two rivers flowing from Lake Timpanogos, one to San Francisco Bay (the R. Timpanogos), the other to Port Orford, Oregon (the Los Mongos R.) where the Rogue River enters the Pacific.
When Francisco Garcés and Pedro Font drew their maps of Spanish Alta California, they did not understand the nature of the Sierra Nevada, nor did they know about the Great Basin between the Sierra and the Rocky Mountains, so they identified rivers from the Sierra with Miera's Buenaventura. Then, when Manuel Augustin Mascaro and Miguel Constanso made the first map of the whole Viceroyalty of New Spain (1784), they built on their colleagues' work and connected the Buenaventura to the Pacific Ocean, in or near San Francisco Bay. Later cartographers of the young United States such as Alexander von Humboldt in 1804, William Clark in 1814 and Zebulon Pike in his book from 1810 believed in the findings of the Spanish cartographers and connected different Californian rivers, that they themselves had seen, with waters in the Rocky Mountains.
As American emigrants began moving through Oregon to California, it became clear that neither the Multnomah (Willamette) nor the Mongos (Rogue) Rivers crossed the Cascades. When Mexican explorers learned more about the Sierra Nevada, questions arose also about the Buenaventura, but Albert Finley in 1826 still drew the river in his influential map, as did others. In 1827, Jedediah Smith crossed the Sierra Nevada and the Great Basin, not finding the Buenaventura; the following year he tracked the western flank of the Sierra in its full length, again without registering a river of the size predicted. In 1841, John Bidwell and Thomas Fitzpatrick led the first group of settlers over the Rocky Mountains to California. They were advised to take carpenters tools with them, to build canoes and sail the Buenaventura from the Great Salt Lake. They found Humboldt River at the edge of the Great Basin and followed it for a while, but there was no trace of a navigable river that would cross the Sierra Nevada.
The Buenaventura River's existence or non-existence was a matter of controversy until 1843, when John Charles Frémont, with Thomas Fitzpatrick and Kit Carson as scouts, led a perilous expedition from the Columbia River to Sacramento, California via the Sierra Nevada. By that time the fact that the Buenaventura River did not flow from the headwaters of the Colorado/Green River was well established among the trappers and guides, but maps continued to show it and other rivers flowing from the region of Great Salt Lake to the sea. On January 27, 1844 at Walker River, he briefly believed himself to have found the mythical river, but it was the result of a faulty measurement. Two days later he discovered his mistake and definitively proved that the Buenaventura did not exist.[1][8] Fremont concluded that the Buenaventura River name originated near the mouth of what is now the Salinas River near Monterey and applied the name to it. As late as 1849 [9] the name "Buenaventura River" was applied to the Salinas River. Even after Fremont conclusively established that the Buenaventura River did not exist as shown on contemporary maps, President Polk and others in 1845 were reluctant to discard official maps as errant.[10]
After the hopes of a waterway from east to west were lost, Frémont and his father-in-law and political sponsor, Senator Thomas Hart Benton, directed their ambitions to a transcontinental railway, which was completed in 1869, after the Mexican-American War of 1846–48 and the American Civil War.