County of spring: Carter County
Location of spring: MO 103, Big Spring - Ozark National Scenic Riverway, Van Buren
"Nearby Big Spring State Park, 4582 acres of Ozark grandeur, founded, 1924, features the natural beauty of the largest single-orifice, fresh water spring in the U.S.
"Big Spring has a maximum flow of 840 million gallons every 24 hours and a daily average of 250 million gallons. The spring discharges about 175 tons of limestone in solution daily. 433 feet above sea level, at the base of a 500-foot cliff, the spring gushes through an impeded opening from an underground stream bed and flows 1,000 feet to Current River, famed spring-formed, spring-fed Ozark fishing stream. Of the 69 springs in the U.S. having a daily flow of 64,600,000 gallons or more, 11 are in the Missouri Ozarks." State Historical Society of Missouri
Marker text:
BIG SPRING
Where Does the Water Come From?
Rainwater moves into underground systems through sinkholes, percolation through stream beds, and seepage through soil and rocks. Dye traces of the Big Spring system (yellow) indicate water comes from an area up to 40 miles away. The trip from surface to spring may require 17 days. Since little filtration occurs in this sponge like system, water-purity is strongly influenced by surface activities.
"The name says it all. Big Spring is indeed a big spring and the biggest in Missouri in terms of average daily discharge with some 276 million gallons of cool spring water (58 degrees Fahrenheit) flowing from it each day. This is one of the largest springs in the world. A dye-trace study has showed that dye introduced into a losing stream 39.5 miles away (near Mountain View) was detected at Big Spring 16 days later. This is the longest distance groundwater trace in the U.S. Large springs such as this depend on large areas of karst landscape to recharge them. The spring is at least 80 feet deep based on research dives.
"The spring run of Big Spring provides cool water that feeds the Current River. Within the spring run, characteristic Ozark fishes include the Ozark sculpin and the bleeding shiner. Star duckweed, a plant species restricted to springs, occurs in the spring branch along with a variety of other plant species characteristic of springs including water starwort.
"Downstream of Big Spring the Current River boasts a fish fauna rich in diversity including colorful darters and shiners (e.g., rainbow darter, bleeding shiner, and rosyface shiner,) and game fishes (e.g., shadow bass or goggle-eye, longear sunfish, walleye, and smallmouth bass). The Current River saddled darter has been located downstream of Big Spring. This fish species occurs only in the Current River watershed and nowhere else in the world. The Current River is of global conservation significance according to The Nature Conservancy and provides habitat for 35 global priority aquatic species of which 25 have their best or only populations on Earth in the river. The Nature Conservancy considers the Current River and its watershed to be the crown jewel of Missouri’s native landscapes. Birding along the Big Spring branch and along the nearby Current River you may spot the rare cerulean warbler. Other birds to look for include the kingfisher, the American redstart, the wood thrush, the red-shouldered hawk, and the northern parula.
The Big Spring area became a state park in 1925 and was developed by the Civilian Conservation Corps during the Depression era of the 1930s. In 1972 the area was transferred to the newly created Ozark National Scenic Riverways." ~ Missouri Department of Conservation