HOT SPRINGS, S.D. – Visitors to Hot Springs can plunge into fun at the largest indoor, geothermal spring-fed pool in the world. Evans Plunge is built over 13 small, sparkling springs and one mammoth spring of warm mineral water, which sits on top of a natural bed of smooth river rocks.

Prized by the Lakota Sioux and the Cheyenne for thousands of years, the valley of healing waters, called Wiwilakahta, was considered a cure-all. According to local legend, a fierce battle was fought on the east summit above the springs and river – now called Battle Mountain – with the Sioux emerging victorious over the Cheyenne for possession of the sacred waters.

The first Evans Plunge was built in 1890 by Fred Evans. Since that time, the crystal clear water has drawn visitors from around the world for rejuvenation, refreshment, relaxation and recreation in a family fun environment.

The large 200-foot long by 50-foot wide pool boasts three water slides – one takes swimmers from inside the building and deposits them into another pool outdoors – a curvy whale slide for kids and a straight 164-foot slide that hydroplanes you across almost the entire length of the pool. There are Tarzan Rings which take you from one side of the pool to the other, hand over hand; fun tubes, kid’s pools and a full service health club offering a cardio room, weight room, water aerobics, land aerobics, mineral water hot tubs, steam room and dry sauna.

For those looking to burn off some energy there is also water volleyball and basketball games to participate in.

If you had a more relaxing day in mind, visit the gift shop and concession stand.

General Manager Vicki Hudson said Fall River, which runs through Hot Springs, stays about 67 degrees year-round. “The geothermal spring that comes up into the pool is 87 degrees. Over the past 100 years, it has lost 10 degrees – it used to come up at 97 degrees,” she said. “Our Mammoth Spring comes up from the bottom of the pool at 5,000 gallons a minute and flows out the side of our building to form the Fall River. We have the cleanest water you will ever swim in; the spring is completely filled with new water every 90 minutes.”

The first wooden building covering the springs in 1890 has been replaced four times, with the latest being cemented block. “They discovered that steel doesn’t work unless it’s stainless steel. It’s like a big old ship – you are constantly maintaining it,” Hudson said.

At the north end of the pool inside the plunge, the Mammoth Spring is known as the “Original Indian Spring.” Prior to 1890, Indians went there to bathe and drink from the springs. Evans Plunge, according to Hudson, was the Black Hills first tourist attraction.

Photo courtesy Evans Plunge Evans Plunge, first built in 1890 by Fred Evans, has drawn visitors from around the world for rejuvenation, refreshment, relaxation and recreation in a family fun environment.