The Arkansas River is one of the major tributaries of the mighty Mississippi River. One of the country's longest rivers, its spanse 1,469 miles (2,364 km), flowing through four states on its way from the Rocky Mountains in Colorado to Arkansas. Historically known to have sustained Native American dwelling throughout its course, the river today offers thrilling opportunities for adventure-seekers, with nearly 152 miles of rapids for whitewater rafting. Besides this, a section of the river is a popular avenue for fishing, with an abundant trout population.