Water seeps into the ground southeast of Great Falls in the Little Belt Mountains, where the Madison Limestone formation is exposed at the land surface, then travels through the formation toward Giant Springs. In the springs area, the Madison Formation lies about 400 feet below the surface, and pressure from overlying rock layers forces the water upward through cracks in the overlying sandstone. The water takes less than 50 years to flow from the Little Belt Mountains to the Giant Springs area and emerges from the ground at a consistent 54 degrees all year long.