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.