Arkansas River

Arkansas River, next to the Missouri the largest affluent of the Mississippi. It is 1514 miles long, rising in the Rocky Mountains, at an altitude of 10,000 feet, on the borders of Utah, and joining the 'Father of Waters' at Napoleon, 275 miles above New Orleans. Flowing generally through a level country, it presents but few obstacles to navigation. The principal difficulty is connected with its periodical rise and fall—the difference between season and season being not less than 25 feet. It varies in width from 150 feet near the mountains, to about a mile in the sandy regions, and is practicable for steamboats, during nine months of the year, to a distance of 800 miles from its mouth. It divides the state which takes its name into nearly equal parts. Its most important tributary is the Canadian River.