Searching for a Mythical River |

Searching for a Mythical River

The men in Lieutenant John Charles Fremontand#8217;s command were a bit confused. They had spent the summer of 1843 trekking west toward the Oregon Country (Pacific Northwest), exploring and mapping as they went. Their orders seemed clear enough. Survey the Oregon Trail by carrying a line of astronomical and barometric observations through to the Columbia River (for a possible transcontinental railroad route), and then retrace their steps back to Missouri. Why then had Fremont ordered his scruffy band of mountain men to head south, down along the eastern side of the Cascades and the Sierra Nevada on their return from the Pacific?

Although Fremontand#8217;s motives will probably remain a bit of a mystery, he was most likely following orders from his father-in-law, Senator Thomas H. Benton, an ardent expansionist and strong proponent of Manifest Destiny. In 1841, Fremont had married Sen. Bentonand#8217;s 16-year-old daughter, Jessie, and the senator chose his new son-in-law, a topographical engineer, as point man for the U.S. governmentand#8217;s ongoing strategy of westward expansion. Mexicoand#8217;s province of California would be the greatest prize of all, but to get it Sen. Benton wanted Fremont to gather detailed knowledge of the western landscape, and if possible, Mexican troop strength.

In his report, Fremont mentioned he was searching for the Buenaventura River, a mythical ribbon of water that purportedly drained west from the Rocky Mountains and flowed all the way to the San Francisco Bay. If true, its existence would greatly simplify travel through the rugged, arid region known today as the Great Basin.

In 1546, a Venetian mapmaker, Giacomo Gastaldi, had placed the and#8220;Strait of Anianand#8221; just about where the todayand#8217;s Bering Strait is located, but for the next 200 years, mariners and explorers looked all over North America for it. (Maps from that era often showed California as a large island, separated from the continent by a narrow waterway.) The idea of a waterway like the Buenaventura had its roots in the long-held hope of a Northwest Passage that would facilitate trade between Europe and Asia, a water route the worldand#8217;s maritime powers had been searching for since Columbus. Whether the Buenaventura was actually a river or a inland arm of the Pacific Ocean mattered little to the empires looking for it, control of such a waterway would give advantage to the country that discovered it first in the exploitation of natural resources.

The erroneous belief in the nonexistent Buenaventura River, as well as other crucial misconceptions of the region, would be corrected by Fremontand#8217;s expedition. As the men explored what today is western Nevada, it quickly became obvious the Sierra Nevada range blocked the possibility of any westbound river from reaching the Pacific Ocean. There were an assortment of maps of the region available before 1843, but ultimately it was Fremontand#8217;s explorations that produced the first reliable maps and placed Western cartography on a scientific foundation. Fremont was also the first to comprehend all the rivers in this region of the country fail to reach the sea, inspiring him to name it the and#8220;Great Basin.and#8221;

Critics have claimed Fremontand#8217;s exploits were never as heroic or extraordinary as he made them out to be, but his biographer Allan Nevins wrote, [Fremont knew] and#8220;how to make an expedition into a new country scientifically profitable and#8212; to take accurate astronomical observation at every halt, record topography, observe botany, soils, and minerals, and draft careful sketch maps.and#8221; There is no doubt that Fremont revealed the contours of the American West and showed emigrants how to get there.

and#8212;Tahoe historian Mark McLaughlinand#8217;s award-winning books are available at local bookstores. Mark can be reached at

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