Limited tours of Great Salt Lake’s mirabilite mounds announced for January

Only visible when the Great Salt Lake’s level drops below the elevation of 4,194 feet, the mirabilite mounds are back and limited public tours are available.

This is only the second time the Great Salt Lake State Park has offered tours of the mirabilite mounds, which were first brought to the park’s attention in Oct. 2019 after a park ranger noticed them. You can see photos of those mounds in our gallery above.

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In a news release, the state park stated:

Geologists investigated, and determined that the mirabilite is precipitating from warm, high salinity sulfate-rich springs, visible only when the lake level falls below an elevation of 4,194 feet. A closer inspection of the mounds revealed that they are a built-up collection of crystallized terraces, similar in appearance to the travertine rimstone and dam terraces that form at Mammoth Hot Springs in Yellowstone National Park.”

Public tours of the mounds will happen on two weekends in January — on the 9th and 10th and again on the 23rd and 24th. 

Tours run from 11 a.m. to 4 p.m. and will begin every half hour. Only 15 people are allowed on each tour and registration for the tours is required. 

People can register for tours here and “those attending are advised to wear water-resistant or waterproof boots as the lake water and mud can rise to mid-calf,” a news release stated. “As research into these mounds continues, we are asking that members of the public do not damage these mounds or intentionally remove pieces of them.”