The Lewis & Clark Expedition discovered Giant Springs in 1805. The spring is one of the largest in the country and has a flow rate of 156 million gallons of water per day! The spring’s freshwater stays at 54 degrees. The flow of water is so powerful it pushes the muddy Missouri River back for several miles downstream. In this image, we can see the line between the spring’s water and the Missouri River near the bottom third of the image. This image was taken with a DJI Phantom 4 Advanced piloted by David Daly of Vigilante Drones.