Interesting article on Miracle Hot Springs that also gives insight on the origin of hot springs in the Cascades.
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Miracle Hot Springs has four outdoor pools
(Times-News file photo)

The original spring for Hagerman’s Miracle Hot Springs emerged close to the bank of Salmon Falls Creek. In the 1930s, the owners dug a deep hole wide enough to drop two old car bodies in to cap the spring. A well was drilled through the car tops to install pipe. The original homesteaders built chicken coops, sheep dip vat to kill ticks, and the best-tasting watermelons were grown around the springs.
In 1957, Dean Olsen bought the land and built the first six baths and a small home adjoining them, opening for business in 1960. In the early 1960s, he expanded by building the big outside pools followed shortly with nine private baths.
Miracle Hot Springs continuous flow of natural hot spring water is soft to the touch and odorless with a sensational alkaline pH of 9.6 allowing swimmers to rejuvenate.
Miracle Hot Springs’ remodel has been complete nearly a year now with 15 private hot pools, six VIP pools, and four outdoor public pools open year-round, including holidays.
“Miracle Hot Springs is fed by thermal groundwater in volcanic rocks,” said Shawn Willsey, College of Southern Idaho Professor of Geology. “The source of the water is likely to the south in the higher terrain of Brown’s Bench along the Idaho-Nevada border.”
Nat-Soo-Pah, located in Hollister, comes from a Shoshone word that roughly translates as “magic mineral water.” In the late 1890s, native Shoshone used the hot springs as a wintering area. The Shoshone lived in the nearby foothills and used this spring for baths before homesteaders built bath houses.
According to the Hollister Herald in June 1911, Goat Springs has for a long time served as the bathing resort for citizens of Hollister.
Sometime between 1926 and 1930, the Hot Wells Development Company was formed to develop a natatorium and camping resort.
The artesian spring comes through a layer of iron pyrite “fools gold,” which gives the water in the swimming pool a greenish color. Mineral content includes iron, aluminum, sodium chloride, magnesium, bicarbonate calcium, bicarbonate sodium and sulphate.
“The thermal water comes from rain and snow that falls in the South Hills and moves into the subsurface passing through fractures in the volcanic rocks and ultimately into the 280 million-year-old marine sedimentary rocks below,” Willsey said.
“Here the water moves along fractures, bedding planes, and perhaps small cave systems, dissolving some of the calcium and other elements from the rocks and ultimately discharging as hot, mineralized water at Nat-Soo-Pah. Studies done in this area estimate that the water takes as long as 5,000 years to move through the aquifer in the subsurface. Nat-Soo-Pah appears to lie along a fault zone, which likely contributes to the movement of groundwater in this area.”
Both Miracle Hot Springs and Nat-Soo-Pah are naturally heated by thermal water bubbling up from the high-desert terrain. The water’s temperature ranges from 99 F to 106 F.
“Ultimately, all hot springs in the area owe their existence to the regional volcanic activity of the Snake River Plain during the past 10 million years,” Willsey said. While there is no evidence that magma still exists beneath the Magic Valley, rocks at shallow depths still retain residual heat from the volcanism and therefore are able to heat up groundwater. The heated groundwater is less dense and rises to the surface. Faults, fractures, and other pathways allow the heated water to make it to the surface more quickly..
According to, Idaho has the most usable hot springs in the nation with about 130 soakable out of 340. Ninety percent of Idaho’s 340 hot springs are the result of leftover energy heating water near fault lines. This energy is essentially leftover from a 17-million-year-old meteorite collision, which occurred in southeast Oregon. The other 10 percent of Idaho’s hot springs are from water being heated by active volcanoes, typically at or around fault lines.
The impact of the meteorite was so deep it remains stationary while the North American tectonic plate shifts above it. As the plate slowly moves, the hot spot periodically erupts volcanic lava — leaving a traceable path of volcanic activity behind. This path of volcanic activity is not only responsible for Yellowstone National Park, but for almost all of the hot springs activity in Idaho.

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