First discovered November 9, 1828, by Peter Skene Ogden on his fifth Snake Country expedition. Entering Nevada near present Denio, Ogden came southward along Quinn River and the Little Humboldt River, emerging on the Humboldt main stem near this site. Ogden explored hundreds of square miles of the Humboldt's course, left records of his trail blazing in his journal and first map of the area.

Ogden gave the name "Unknown River" to the Humboldt at this time, as he was unsure where it went. Later, after the death of his trapper Joseph Paul, Ogden renamed the stream Paul's River, then Swampy River, 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 or Mary's River were commonly used names for the Humboldt prior to the publication of John C. Fremont's map in 1848.

The Humboldt was the only natural arterial across the Great Basin. It funneled thousands of emigrants along its valley en route to the Pacific Coast during the period of 1841 - 1870.

State Historic Marker No. 22
Nevada State Park System
Northeastern Nevada Historical Society