8 Historical Events That Defined Montana

Vanessa Locampo
Last Updated: February 27th, 2023

The many events of Montana’s long and colorful history have all contributed to the unique state it now is.

The historical events that defined Montana led to the growth of the state, its distinctive culture, and its lasting legacy that visitors travel from all over the country to experience today.

Historical Events that Defined Montana

The Louisiana Purchase (1803)

the louisiana purchase

In 1803, the United States purchased around 827,000 square miles of land from France, which in effect almost doubled the size of the country. The land that was purchased sat west of the Mississippi River and led to the formation of parts or all of 15 states from the Mississippi River to the Rocky Mountains.

Though it wasn’t known as Montana at the time, the United States acquired most of what would become the Treasure State in the Louisiana Purchase.

Thomas Jefferson paid $15 million for the gained land, which added up to the steal price of around four cents an acre.

The Louisiana Purchase wasn’t just integral to the creation of Montana, but also to the history of the entire country.

Historian and director of the New Orleans-based Eisenhower Center for American Studies, Douglas Brinkley, says per Smithsonian, “With the Declaration of Independence and the constitution, [the Louisiana Purchase] is one of the three things that created the modern United States.”

The Lewis and Clark Expedition (1804 – 06)

lewis and clarks' winter camp
Image: Don Graham

Following the Louisiana Purchase, Thomas Jefferson sent a military expedition west to explore the newly acquired territory. The expedition, also called the Corps of Discovery, was led by Jefferson’s personal secretary, Captain Meriwether Lewis, and the U.S. Secretary of War Lieutenant William Clark.

The expedition consisted of 31 men, one Shoshone woman—the famous Sacagawea—and her baby, traveling towards the Pacific Ocean coastline.

What Was the Purpose of the Lewis and Clark Expedition?

They’d been instructed to map a new path to the ocean, find the legendary Northwest Passage water route, connect with Native Americans, send back flora and fauna specimens for study, and record their findings.

Sacagawea served as an interpreter during the trip and also helped the men to identify edible plants, acquire horses and supplies, and prevented conflict with other tribes they came into contact with along the way.

Where Exactly Did the Lewis and Clark Expedition Go?

pompeys pillar

The Lewis and Clark Expedition began in Philadelphia and ended in Oregon, with a significant portion of the route passing through Montana.

Their trail covered more miles in Montana than any other state, beginning at the North Dakota border and continuing all the way to the Idaho border.

On their return, the Corps of Discovery split up. Lewis traveled north with half the men while Clark and Sacajawea stayed south and eventually came to the Yellowstone River.

How Did the Expedition Affect Montana?

how did the expedition affect

The explorers left their legacy in Montana, with the Lewis and Clark Trail today a huge point of interest for the state’s tourism.

They passed, sometimes named, several local landmarks, including Decision Point, Fort Benton, the Great Falls of the Missouri, and Pompey’s Pillar National Monument.

Ultimately, the Lewis and Clark Expedition changed the history of Montana and the rest of the country by mapping uncharted land, making discoveries about plants and animals, and later regaling stories of their adventures in the west that stirred interest in other Americans.

Their journey inspired millions of others to migrate west, beginning the great westward expansion.

The Discovery of Dinosaur Bones (1854)

the discovery of dinosaur bones

When it comes to paleontology, Montana is one of the world’s top destinations.

The state’s rich dinosaur history dates back to 1854 when naturalist Ferdinand Hayden discovered the remains of a dinosaur near Judith Landing in the Missouri River Breaks National Monument.

This marked the first instance of dinosaur fossils found in North America. Hayden discovered what paleontologist Joseph Leidy later called Trachodon, a duck-billed dinosaur.

The discovery was the beginning of dinosaur remains being unearthed in Montana and set the tradition for a long list of subsequent discoveries to take place in the years following.

What Notable Dinosaurs Discoveries Took Place in Montana?

carter county museum

Later in 1902, the first identified tyrannosaurus rex in the world was also found in Montana, in the Hell Creek area near Jordan.

This was discovered by paleontologist Barnum Brown, which put Montana on the map for its association with the famous carnivore.

Another tyrannosaurus rex was uncovered near Fort Peck Lake in 1997, gaining worldwide recognition for being the most complete specimen of its kind to have ever been found.

The real skeleton is still available for viewing at the Museum of the Rockies in Bozeman. And again in 2001, paleontologists uncovered a juvenile tyrannosaurus rex in Carter County.

By 1936, Montana had made a name for itself around America and the world for its many dinosaur fossils. The first county museum in the state, Carter County Museum, was established in Ekalaka that year purely to exhibit dinosaur remains that were located in Carter County.

Egg Mountain, near Choteau, Montana, was the location of the discovery of the first baby dinosaur bones in North America. They were found here in 1978 and are now exhibited at the Montana Dinosaur Center in Bynum.

Paleontologists unearthed a nearly complete brachylophosaurus near Malta in 1994, naming the skeleton “Elvis” because the first bone they uncovered was the creature’s hip bone. Elvis is on display today at the Phillips County Museum in Malta and Bozeman’s Museum of the Rockies.

In 2001, the Guinness Book of World Records’ best-preserved dinosaur ever found was discovered near Malta, Montana. The majority of “Leonardo” the brachylophosaurus was fossilized, leading to his nickname “the mummy”.

One of the most popular highlights in Montana today is the Dinosaur Trail, which runs across 14 locations throughout the state, including museums and state parks.

Three of the 14 locations allow guests to participate in field digs, including the Montana Dinosaur Center, Great Plains Dinosaur Museum, and the Carter County Museum.

The Montana Gold Rush (1862)

the montana gold rush

The presence of gold and silver mines dotted across Montana in the 19th century led to the nickname “the Treasure State”.

The Montana Gold Rush, which began in 1862 in the state’s southwest, drove mass immigration into the territory and also led to the establishment of towns and cities that are standing today, still basking in the glory of their mining legacy.

Brothers James and Granville Stewart and their partner Reece Anderson were the first to discover gold in Montana at Gold Creek, in 1858. However, the rush didn’t occur until 1862, when news broke of a sizable strike at Grasshopper Creek by John White.

How Did the Discovery of Gold Impact Montana?


This first strike led to five million dollars in gold in its first year (Digital Public Library of America).

Migrants arrived from all over the United States and abroad to reap the benefits, which eventually led to the settlement of the infamous town of Bannack.

The embodiment of Wild West gang violence, the town became Montana’s first territorial capital in 1864.

The second strike of gold came in May 1863, in Alder Gulch. As aspiring miners flooded to the area, a number of new settlements were created to accommodate the influx, including Virginia City and Nevada City.

No less than 10,000 miners soon arrived in the area, and Virginia City became the second territorial capital in 1865.

The third and final gold strike took place at the aptly named Last Chance Gulch by four miners from Virginia City. Last Chance Gulch generated 19 million dollars in gold over the next four years, and the town of Helena was established in 1864.

Helena continued to prosper after the gold rush and remains the state’s capital today.

How Did the Gold Rush End?

Gold mining began to decline in the 1890s, making way for a boom in copper mining and the flourishing of towns such as Butte and Anaconda.

Once the grounds were no longer generating large amounts of gold, many of the towns that had been established were abandoned.

The gold rush attracted migrants to Montana in the thousands and led to the creation of towns, communities, and ranches. Whether or not these are still standing today, they shaped the way of life in Montana during the 19th century and had a lasting impact on the molding of the local culture.

In modern times, tourists still visit Montana to witness the remnants of mining towns and even try their hand at panning gold.

The Battle of the Little Bighorn (1876)

the battle of the little bighorn

The Battle of the Little Bighorn was an armed conflict between United States federal troops and Northern Plains Indians taking place in 1876. Also referred to as Custer’s Last Stand, the federal troops were led by Lieutenant Colonel George Armstrong Custer.

The Northern Plains Indians were made up of Lakota (Teton or Western Sioux), Northern Cheyenne, and Arapaho warriors. They were led by several famous chiefs, including Sitting Bull, Crazy Horse, Chief Gall, Lame White Man, and Two Moon.

The Lakota Indians called the fight the Battle of the Greasy Grass. It’s not known for certain how many Indian warriors there were overall, but some historians speculate there were around 2,500.

What Led to the Battle of the Little Bighorn?

chief sitting bull

In 1868, several Lakota leaders signed the Treaty of Fort Laramie, which created a reservation in present-day South Dakota and would require the tribes to give up their nomadic life and rely on government subsidies.

However, some Lakota leaders, like Sitting Bull and Crazy Horse, rejected the idea. Those bands of hunters and warriors who didn’t sign the treaty came into conflict with settlers and enemy tribes outside the boundaries of the reservation land.

Tension escalated between the tribes and the United States when gold was discovered in the Black Hills, resulting in an influx of migrants to the area in violation of the treaty. 

The United States attempted to purchase the Black Hills from the Lakota but their price was rejected. This led to the Commissioner of Indian Affairs issuing a decree requiring all Sioux to report to a reservation by the end of January 1876.

When the Indians ignored the order, the military became involved. The Lakota and Cheyenne were now considered “hostile” and a campaign set out to move them to the reservation by force.

The eventual battle, led by Custer and the 7th Cavalry, took place along the Little Bighorn River in south-central Montana.

What Happened at the Battle?

what happened at the battle

Custer approached a large village of Lakota and Cheyenne near the river, and when he was spotted by the village people, he made the swift decision to attack rather than scouting the village.

He is believed to have misjudged how many warriors he was up against, underestimating by hundreds.

He split his forces and had his Major Reno launch an attack from the south of the village. When they were challenged by a significant force from the village, they retreated to the hills and were eventually rescued by reinforcements.

Meanwhile, Custer is believed to have attacked from the north of the village and was likely defeated by a larger Indian force. He ended up on a hill with only 50 or so of his men left, surrounded by warriors.

Custer and all the men under his immediate command were killed, which made the Battle of the Little Bighorn the most influential Native American victory in the Plains Indian War.

It was also the worst U.S. Army defeat and outraged white Americans at the time. The battle reinforced the harmful stereotype of the Indians as bloodthirsty and savage.

Even though the Battle of the Little Bighorn was a victory for the Lakota and the Cheyenne, it motivated the United States to force native people onto reservation lands with even more conviction.

Within one year of the fight, more troops were sent to conquer the Northern Plains Indians, most surrendered, and the Black Hills area was stolen by the U.S. government with no compensation.

The Arrival of the Northern Pacific Railway (1880)

the arrival of the northern pacific railway

The arrival of the first rails to Montana led to immense growth and the formation of the state as we know it today.

The first tracks were constructed in 1880 when the state was still a territory. They were laid over the Continental Divide at the Idaho-Montana border.

Communities in the area greatly anticipated the arrival of the Northern Pacific Railroad in Montana, which would eventually travel from Wisconsin to Puget Sound, Washington.

The railroad boosted several local economies; copper production in the community of Butte produced more than 9 million pounds of copper within a year of the first constructed railway.

The railroad was based in Saint Paul, Minnesota, and linked to a large area across the states of Montana, Idaho, Minnesota, North Dakota, Oregon, Washington, and Wisconsin over around 6,800 miles of track.

How Did the Railway Benefit Montana?

The rails transported Montana’s resources to the rest of the country and brought in equipment and supplies more quickly, which local farmers and others used to produce more goods for the market.

The main industries that gained most from the Northern Pacific Railway included wheat and cattle farming, timber, and mining.

They also made it easier for locals to travel around Montana and paved the way for migrants and settlers to spread all over the state.

The Northern Pacific Railroad was in operation until 1970, when it merged with other rail lines to form the Burlington Northern Railroad.

The Burlington Northern Railroad became the BNSF Railway in 1996 after assimilating with the Santa Fe Railway.

The Establishment of Glacier National Park (1910)

the establishment of glacier national park

One of Montana’s greatest gifts to the world is its stunning natural landscape. The backdrop made up of towering mountains, grassy plains, and crystalline rivers and streams has lent itself to the formation of several national and state parks.

Along with Yellowstone National Park, some of which is located in Montana, the state’s greatest natural area is Glacier National Park, the Crown of the Continent.

Of course, the park predates human activity in the area and can be traced back more than 10,000 years.

Several Native American tribes inhabited the area before the arrival of white settlers; the Blackfeet Indians lived in the prairies to the park’s east while the Salish and Kootenai Indians resided to the west.

The first European explorers arrived in the area to hunt after white settlement. Eventually, miners arrived during the Montana Gold Rush, before settlers came looking for land.

When the 20th century dawned, people in the area began to understand the sheer beauty of the land. Those with influence, including George Bird Grinnell, began to campaign for the creation of a national park.

When Was the Park Established?

glacier national park

The park was established in May 1910 as the 10th national park in the country. Curious guests traveled from all over the country on the Northern Railway to witness the alpine beauty of the park and stay in the chalets scattered throughout.

In 2010, Glacier National Park celebrated its centennial anniversary, during which 2.2 million visitors traveled to the park.

Today, it remains one of Montana’s most treasured highlights and has significantly increased the state’s flourishing tourism industry.

The Smith Mine Disaster (1943)

the smith mine disaster

In 1943, Montana experienced the worst coal mining disaster in its history as a state. The Smith Mine Disaster was in the top 50 worst coal mining disasters in the United States.

On the cold morning of February 27, a build-up of methane gas approximately 7,000 feet below the ground caused an explosion at Smith Mine in Carbon County. There were 77 miners working at the time, and the blast killed all but three of them.

Locals were only alerted to the explosion when they noticed smoke floating out of the mouth of the mine, as the detonation had happened so deep beneath the Earth’s surface.

Rescuers came from nearby mines and the town of Butte. Family members also arrived to help, but the fumes from the explosion were so toxic that people could only stand in the mine for five minutes at a time.

Perhaps the most tragic part of the Smith Mine Disaster is that not all the miners were killed on impact; some survived for up to an hour and a half after the explosion. Some are believed to have written messages to their families with chalk in the mine.

The blast led to the establishment of an emergency hospital in Red Lodge, where more than 100 rescuers were taken after they suffered injuries during the rescue attempt.

Following the tragedy, the Smith Mine remained closed forever. The local population suffered a significant decline and also never fully recovered.

Historical Events that Defined Montana – Conclusion

From the Louisiana Purchase to the first strike of gold to the arrival of the Northern Pacific Railroad and the formation of Glacier National Park, Montana has been shaped by a distinctive history.

For better or worse, these events have created the Treasure State as we know it today.

Have any questions about the most significant events in Montana history? Let us know in the comments below!

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About The Author

Vanessa Locampo

Vanessa is an Australian-based freelance writer and editor with a BA in Creative Writing. She’s passionate about creating travel content that inspires her readers to take a leap of faith and power through their bucket lists. When she’s not writing (with her border collie asleep at her feet), she’s devouring books, exploring the world, or planning her next trip.

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