<P> At 1,469 miles ( 2,364 km ) , it is the sixth - longest river in the United States , the second - longest tributary in the Mississippi -- Missouri system , and the 45th longest river in the world . Its origin is in the Rocky Mountains in Lake County , Colorado , near Leadville . In 1859 , placer gold discovered in the Leadville area brought thousands seeking to strike it rich , but the easily recovered placer gold was quickly exhausted . The Arkansas River 's mouth is at Napoleon , Arkansas , and its drainage basin covers nearly 170,000 sq mi ( 440,300 km2 ) . In terms of volume , the river is much smaller than the Missouri and Ohio Rivers , with a mean discharge of roughly 41,000 cubic feet per second ( 1,200 m / s ) . </P>
<P> At 1,469 miles ( 2,364 km ) , it is the sixth - longest river in the United States , the second - longest tributary in the Mississippi -- Missouri system , and the 45th longest river in the world . Its origin is in the Rocky Mountains in Lake County , Colorado , near Leadville . In 1859 , placer gold discovered in the Leadville area brought thousands seeking to strike it rich , but the easily recovered placer gold was quickly exhausted . The Arkansas River 's mouth is at Napoleon , Arkansas , and its drainage basin covers nearly 170,000 sq mi ( 440,300 km2 ) . In terms of volume , the river is much smaller than the Missouri and Ohio Rivers , with a mean discharge of roughly 41,000 cubic feet per second ( 1,200 m / s ) . </P>
where does the arkansas river flow into the mississippi
where does the arkansas river flow into the mississippi
Napoleon , Arkansas
Napoleon , Arkansas