The spring remains between 55 and 58 degrees year round and has a glorious aquamarine hue thanks to minerals dissolved in the water. Watercress abounds in the cold water, providing shelter for a large number of aquatic life forms including periwinkle snails, insect larvae and a variety of fish. Burrowing crayfish leave their mounded tunnel openings along the bank. Birds, deer and mammals such as squirrel and woodchucks also visit the spring.
By the turn of the 20th century the Current River valley was becoming popular with vacationers. The same qualities that made settling the area difficult were drawing visitors from around the country. The wildness of its countryside, the clarity of its water and the remoteness from the outside world, made Big Spring a peaceful escape from the demands of everyday life.
Big Spring became a State Park in 1924, Missouri's first. The Civilian Conservation Corps (CCC) arrived in the mid-1930's, helping to conserve the area's resources and provide increased visitor facilities. The stream from Big Spring to the Current River was dug by the CCC to control the flow of the spring.
Ozark National Scenic Riverways was established in 1964. Big Spring, along with Alley Spring and Round Spring State Parks, were placed under National Park Service management in 1969. With these additions, Ozark National Scenic Riverways was complete.