The Arkansas River is a major tributary of the Mississippi, running for some 1,500 miles from its source in the Rocky Mountains near navref Leadville, Colorado. It passes through the states of Colorado, Kansas, Oklahoma and Arkansas before reaching the Mississippi in a broad, many-channelled delta.
The Arkansas is the largest river contained entirely within the boundaries of the Amtrak Federation, and is bridged in several places allowing wagon-trains easier access to lands to the north. The Pueblo way-station is located close to the river's headwaters in an area easily forded by wagon-trains.