The Bizarre Boulders That 'Sing' Are In A Breathtaking Mountainous Montana Destination

Montana is full of natural beauty, from the rugged mountains and glacial lakes in the "Crown of the Continent" (Glacier National Park) to kaleidoscopic hot springs in Yellowstone National Park, not to mention the vast prairies in the northeast – all of which help the state earn its unofficial nickname, the "Last Best Place." Of Montana's many outdoor attractions, one of the more unusual is a unique geological formation where rocks chime like bells. 

The aptly named Ringing Rocks is located about 20 miles east of Butte in southwest Montana. To the observer, the site looks like any other jumbled boulder field. But when you strike one of the rocks with a hammer, it emits an unexpected, resonant peal. The geological abnormality is part of the Boulder Batholith, a 1.2 million-acre mass of igneous rock created by volcanic eruptions millions of years ago. The 160 acres known as Ringing Rocks is the only segment of the batholith where the rocks chime — and there's not an easy answer for why. 

While there isn't one agreed-upon reason for the bizarre acoustics at Ringing Rocks, there are a few theories. Some geologists believe the sound is produced because of the composition of the rock and the specific way the rocks eroded over time. Another theory says it's all about the rock's internal structure of tightly packed crystals that allow sound waves to travel easier and create the ringing sound. Yet another idea is that the rocks are actually the eroded remnants of the spire rocks on Homestake Pass, a nearby mountain pass. 

One of the earliest known mentions of the site came in 1933, and the ringing remains a scientific mystery more than 90 years later. "No one REALLY KNOWS why the rocks ring," Joan Gabelman, a certified mineral examiner for the Bureau of Land Management, emailed to the Daily Montanan. Ringing Rocks is one of only two known places in the United States where this type of chiming rock formation exists. The other lies in Ringing Rocks County Park in Bucks County, Pennsylvania, between Philadelphia and New York City. The Montana destination is more remote – and harder to reach – but offers an uncrowded experience. Just be sure to bring your own hammer.

The former mining town of Butte, now boasting a population of about 36,000, serves as home base for a trip to Ringing Rocks. From there, visitors hoping to hear the chiming rocks can head east on Interstate 90 and take Exit 241, called the Pipestone Exit. Travelers will go east on a gravel road that parallels the interstate for 3/4 of a mile, and then turn north onto another gravel road.

After that turn, a rocky, rough, 3-mile road leads to Ringing Rocks. A high-clearance, four-wheel-drive vehicle is recommended in order to reach the site. Some visitors decide to park their vehicles about 1 mile out and hike the remainder of the journey. "Made it all but about 700 feet from the top in a 4x4 Jeep," Tyler Bass wrote on Google Reviews earlier this year. "Awesome trail, fun hike with amazing views, and awesome experience with the different tones of the rocks!"

When you're done with the musical rocks, take some time to explore Butte, which is home to the must-visit World Museum of Mining. A pint and a pizza at Butte Brewing Company will help round out your trip.