Emerging near the Missouri border in north central Arkansas, the Spring River has been described as the state's most dependable natural stream. Mammoth Spring, flowing at over nine million gallons of 58-degree water per hour, serves as the headwaters for the river and provides plenty of fresh water throughout the year. The river is crystal-clear, with long pools and whitewater falls. The scenery is mostly hardwood forest with some rocky bluffs. Access is from U.S. 63, which parallels much of the upper Spring. The constant flow from Mammoth Spring makes the Spring River one of the state's best year-round floats even during the summer months when river levels tend to fall.