Mammoth Spring

Mammoth Spring is a very large first magnitude spring. It is the largest spring in the state of Arkansas and the third largest spring within the Ozark Plateau region behind the Big Spring and Greer Spring. It is located in Mammoth Spring State Park, an Arkansas state park, in the extreme north-central part of the state at the town of Mammoth Spring. The outlet pool of the spring is located a just to the east of US Highway 63 (US 63) and roughly 500 feet (150 m) south of the Missouri border. Mammoth Spring's large outlet pool can easily be seen by travelers on US 63. The spring's large volume of water rushes a few hundred feet before merging with the Warm Fork of the Spring River to form the Spring River headwaters. The cold water provides excellent trout fishing conditions in addition to ample water for float trips on the Spring River. It was declared a National Natural Landmark in June, 1972.

Description

Rainfall in southern Missouri seeps into the water table and flows through a vast system of passages and cavities. These cavities form a main channel and the groundwater reaches the surface at the town of Mammoth Spring, Arkansas. The emerging water forms a 10-acre (40,000 m²) spring pool that drains over a high stone dam. The spring generates a flow of 10 m³/s (344 cubic feet per second). The water emerges at a constant 14 °C (58 °F). The spring itself cannot be viewed at the Mammoth Spring site because its mouth is more than 21 m (70 ft) below the surface of the large spring pool.