Born in Demark in 1800, Lassen was practicing his trade as a master blacksmith in Charlton County, Missouri in the 1830s, where he met Swiss adventurer John Sutter. He journeyed overland to Oregon in 1839, then joined Pablo Gutierrez, Sebastian Keyser and Niklaus Allgeier, (who had accompanied Sutter overland to Oregon a year earlier) aboard the Lausanne down the coast to Bodega Bay. Traveling on horseback from there, the men were warmly welcomed when they reached Sutter’s Fort, although Lassen spent the winter of 1840-41 in San Jose. Returning to the Cosumnes River, Lassen established a small ranch there, did considerable work for John Sutter, and helped Charles Weber establish a new settlement now known as Stockton. After becoming a Mexican citizen in 1843, Lassen acquired a 22,000-acre land grant in present day Tehama County where he raised cattle, wheat and grapes. His new route to the gold fields, Lassen’s Trail, brought thousands of 49ers to his ranch but fell into disuse by 1852 because of its long detour to the north and its difficult terrain. Lassen was not successful at gold mining, but even near 60 years old never gave up his interest in prospecting. Lassen was murdered in 1859 while prospecting with companions; no trace of his attackers was ever found.