Little is known of his early life except that Farnham received a fair education.
As a clerk Farnham joined the Astoria sea expedition that left New York on the Ton- quin, September 6, 1810. In the Oregon country he was one of the most active and adventurous of the party and figured in almost all of the exciting incidents that marked the brief history of the enterprise.
On the sale of Astoria to the North West Company, November 12, 1813, he was chosen by Hunt to carry to Astor the company records and the net proceeds of the sale, consisting of about $40, 000 in sterling bills on London.
Embarking on the company’s brig Pedlar, Farnham sailed, April 3, 1814, and was landed at Kamtchatka, whence he started afoot, carrying a small pack of provisions, across Siberia. This extraordinary exploit, characterized by his friend Darby as a feat that for bravery, danger, and daring was never equaled by any other man, was successfully accomplished. After enduring great sufferings from hunger and exposure, at one time being reduced to the necessity of cutting off and eating the tops of his boots, he reached Saint Petersburg, and later Copenhagen.
From the latter port, on or about October 16, 1816, Farnham sailed for Baltimore, ultimately delivering the papers consigned to him into Astor’s hands. For the remainder of his life he continued in the employ of Astor.
In 1817 - 1819 Farnham was the manager of the American Fur Company’s business on the upper Mississippi. For an alleged violation of the trading laws he and his companion, Daniel Darling, were arrested in the fall of 1817, but on a suit brought by the company were awarded a verdict of $5, 000.
In 1819 Farnham ventured into the Missouri River trade, but from 1821 was again active on the upper Mississippi. In the same year he began to acquire land in the village of Portage des Sioux, in northeastern Missouri, where he established a well-stocked farm and built a beautiful home.
Early in 1832 Farnham journeyed east. In October, some months after his return, he went to Saint Louis, and on his arrival was stricken with cholera, dying within two hours on October 23, 1832. Russel Farnham was buried in the Catholic cemetery, Saint Louis, Missouri.
Russel Farnham was described by his friend Darby as of ordinary size, with a powerful frame, and his Copenhagen passport, not quite tallying with Darby as to his stature, adds the information that his hair was light and curly and that he had brown eyes. Farnham was companionable and sociable.
Quotes from others about the person
"The best meaning and one of the most sanguine of men. " (Ramsay Crooks)
In 1820, Russel Farnham married Agathe Wood.
On October 27, 1829, at St. Louis, Farnham married Susan, the daughter of Charles Bosseron, a French settler of wealth and position.
Russel Farnham had two children.