The Hall Family Travels Blog

Over the last few months of traveling, we’ve had the pleasure of experiencing so many beautiful landscapes across the country, filled with winding rivers, rocky mountains, and long fields of wildflowers. But here in Montana, we discovered someplace that required us to go underground to truly appreciate it.

Tucked beneath the mountains just outside of Whitehall, Lewis & Clark Caverns is a world completely different from the Montana landscape above it. A two-hour tour took our family through a maze of limestone chambers, squeezing through narrow passages and stopping to admire formations that took thousands—even millions—of years to create. We weren’t quite sure what to expect when we signed up for the cave tour, having been through various other caverns before, but by the time we emerged back into the sunlight, it had easily become one of our favorite cave experiences we’ve ever done.

The Classic Cave Tour

We signed up for the Classic Cave Tour and headed to the state park on a Friday in August. The Classic Cave Tour is a guided 2-mile tour that begins with a ¾-mile walk up the mountain, gaining about 300 feet in elevation before reaching the cave entrance. From there, our guide led us through another ¾ mile inside the cavern, and we finished with a ½-mile walk back to the parking lot.

The entire tour takes about two hours, includes around 600 stairs, and requires navigating turns, bends, ducking, squeezing through tight spaces, and even sliding along parts of the route. In other words, it was much more than simply walking through a cave—and we loved it! You can check out a video of the tour on our Instagram page here.

Inside the cavern is obviously the best part of the tour. Imagine standing in a completely dark room beneath the Montana mountains, surrounded by formations that have been growing for thousands of years—and realizing that everything around you was shaped one tiny drop of water at a time.

That’s the experience of exploring Lewis & Clark Caverns.

Our guide, Deedee, shared wonderful stories and informative history as we traveled through the different sections of the cavern. Having a knowledgeable guide and the accompanying information made the journey that much more enjoyable. We weren’t simply walking around looking at rocks; we were learning why they looked the way they did, how they formed, and what made this particular cave so special.

It turned what could have been just another fun hike into an immersive learning experience. There was something pretty humbling about standing beneath the earth, surrounded by formations that may have been developing for millions of years.

How the Caverns Were Formed

One of the things that made the tour so fascinating was learning that the cave we were walking through was essentially created by water—and that same water is still slowly creating the formations inside it today.

The limestone began forming roughly 330 million years ago, when a warm, shallow sea covered this part of Montana. Over time, the calcium-rich remains of marine organisms accumulated on the seafloor and eventually became the limestone that now makes up the cavern.

Much, much later, rain and snowmelt began working their way through cracks in the porous limestone. As the water moved through the soil, it absorbed carbon dioxide and became slightly acidic. That weakly acidic water slowly dissolved the limestone as it seeped underground, gradually enlarging tiny cracks and openings into passages and chambers.

In other words, the cavern wasn’t carved out all at once. It was slowly dissolved into existence, one tiny bit of limestone at a time.

But then something pretty amazing happens.

From Dissolving Away to Building Anew

Once the mineral-rich water reaches the cave, the process essentially reverses. As water drips from the ceiling, it releases carbon dioxide and leaves behind tiny amounts of calcite, a mineral made of calcium carbonate. Drop after drop, year after year, century after century, those tiny deposits accumulate.

That’s how stalactites grow down from the ceiling and stalagmites grow up from the floor. Eventually, the two can meet and form columns. Other formations our guide pointed out, such as flowstone, popcorn and helictites, develop in different ways depending on how the water moves and where the minerals are deposited.

The formations grow incredibly slowly, although the exact rate varies depending on the amount of water, mineral content and other conditions within the cave. Some cave formations can take roughly a century to grow just an inch! That’s why there are strict rules to not touch anything.

Standing there looking at enormous formations that have been developing for thousands—or potentially millions—of years, it was pretty incredible to think about how much time and how many drops of water went into creating what we were seeing.

A Cave With Quite a History

Before going to the caverns, we thought we’d brush up on our history and relearn about Lewis and Clark, since these were the “Lewis and Clark Caverns.” We quickly learned from our guide that Lewis and Clark actually had nothing to do with discovering the caverns.

In fact, they never explored the cave at all.

The Lewis and Clark Expedition traveled through this general area in 1805, following the Jefferson River below the caverns. The cave was later named in their honor by President Theodore Roosevelt, but there is no evidence that the explorers ever knew what was hiding beneath the mountainside.

The caverns are thought to have been known to Native Americans long before they became a tourist attraction, although much of that early history is uncertain. The modern history of the cave begins in the late 1800s, when local residents began exploring the passages.

Eventually, word spread about the impressive formations underground, and people started seeing the potential for tourism.

Enter Dan Morrison

One of the most interesting characters in the cave’s history was a local prospector and businessman named Dan Morrison. Morrison became fascinated with the cavern and began developing it as a tourist attraction around the turn of the century.

Early visitors didn’t have the paved walkways, lighting and carefully developed trails that we have today. Morrison built wooden stairways and other improvements to help people enter and explore the cave, and he promoted the attraction as a tourist destination.

There was just one problem. The land wasn’t actually his.

The Northern Pacific Railroad eventually claimed ownership of the land containing the cave, leading to a legal battle that the railroad ultimately won in 1908. Rather than develop the cavern themselves, the railroad transferred the property to the federal government for preservation.

After the government took over the property, the cave wasn’t immediately developed into the attraction we know today. The entrance was locked for years, but Morrison reportedly continued cutting the locks and taking people into the cave until his death in 1932.

In 1937, the property was transferred to the State of Montana and became Montana’s first state park.

Planning Your Visit

If you’re thinking about visiting Lewis & Clark Caverns, there are a few things you’ll want to know before you go.

The park offers several different cave-tour options between May 1 through September 30. We chose the Classic Cave Tour, which gives you the most immersive cave experience, but does have some age restrictions and physical requirements for safety. The tour lasts approximately two hours and involves a significant amount of walking, stairs and navigating through tight areas.

Tour season: May 1 – September 30

Cave Tour Fees: $15/adult, $10/child (additional $8 park entrance fee for non-residents)

Reservations: Can be made online in advance or in person on a first-come first-serve basis. Reservations are strongly recommended as tours do fill up quickly!

Tour times: Check the website here for current information.

The cave stays cool even during the heat of summer, so bringing a light jacket or extra layer is a good idea. You’ll also want comfortable, sturdy shoes because this isn’t a leisurely stroll. There are plenty of stairs, uneven surfaces and sections where you’ll need to duck, bend or squeeze through.

Because the cave is a protected natural environment, visitors are expected to stay with their group and are not allowed to bring any bags inside and only plain, unflavored water is allowed. It’s especially important not to touch the formations. The oils and dirt from our hands can damage delicate cave formations, and considering how incredibly slowly they grow, it’s easy to understand why protecting them matters.

I’d also recommend allowing some extra time before or after the tour to enjoy the state park itself. The cave is obviously the main attraction, but the surrounding Montana landscape is beautiful, and there are trails, picnic areas and other things to explore around the park.

Was It Worth It?

For our family, absolutely. 10/10 recommend!

We’ve visited other caves and caverns during our travels, so we weren’t sure if Lewis & Clark Caverns would feel like something we’d seen before. It didn’t. The combination of the physical adventure, the incredible formations, the history and having a guide who could explain what we were seeing made it a really memorable experience.

We also appreciated that it was something we could enjoy as a family without spending a fortune. The tour gave us a couple of hours of entertainment while also turning into an unexpected science and history lesson for the kids.

For the price, the experience, and the sheer uniqueness of it, we’d absolutely recommend adding Lewis & Clark Caverns to your Montana itinerary.