In 1808 the Osage moved from their homelands on the Osage River to western Missouri.

They built a fort and trading post on the Osage River in Big Osage territory.

In return, Chouteau was given a six-year monopoly on trade along the Osage River.

The county was organized January 29, 1841, and named for the Osage River.

It is located about sixteen miles west of Osceola, situated on the north side of the Osage River.

On some low ground on the north side of the Little Osage River, Fort Lincoln was established.

June 1 - The expedition reaches the Osage River.

Sometime in the mid-1920s, Street's funding dried up and he had to abandon the idea of the first hydroelectric power plant on the Osage River.

Sunk at the mouth of the Osage River, it became the first wrecked steamboat on the Missouri.

The Osage River is one of the larger rivers in Missouri.