Peter Skene Ogden first discovered the Humboldt River on November 9, 1828, during his fifth Snake Country Expedition. Entering Nevada near present Denio, he came southward along Quinn River and the Little Humboldt River, emerging on the Humboldt main stem near this site. He explored hundreds of square miles of the river's course and left records of his trailblazing in his journal and first map of the area. Unsure where it went, Ogden first called it "Unknown River." Later, after the death of his trapper Joseph Paul, he renamed the stream Paul's River, then Swampy River, and finally Mary's River, from the legendary Indian wife of one of his trappers. In 1833 the Bonneville-Walker fur party named it Barren River. Ogden's River or Mary's River were commonly used names for the Humboldt before the publication of John C. Fremont's map in 1848. The Humboldt was the only natural arterial across the Great Basin and funneled thousands of emigrants along its valley en route to the Pacific Coast during the period 1841-1870.