Montana's Largest and Smallest Cities

Updated: February 2, 2026

Montana's biggest cities and tiniest towns show how different life can be in the same state. Today, Billings is still the largest city, while Ismay remains the smallest incorporated town in Montana.

Largest cities today

• Billings is Montana's largest city, with about 121,000-123,000 people as of the mid-2020s.
• Other major cities include Missoula (about 78,000 people), Great Falls (about 60,000), Bozeman (about 58,000), and Butte-Silver Bow (about 36,000).
• These cities have things you expect in bigger places: busy main streets, shopping areas, hospitals, colleges, and sports events.

Smallest town: Ismay

• Ismay, in Custer County, is the least-populous incorporated town in Montana, with only 17 residents in the 2020 census and about 20-21 people in recent estimates.
• With so few people, almost everyone in town knows each other, and community events can feel like one big family gathering.

Urban and rural Montana

• Montana's population was 989,415 in the 2010 census and grew to about 1,084,225 by 2020-an increase of about 9.6 percent, similar to what your article mentions.
• Around 44 percent of Montanans live in rural areas, meaning more than half now live in towns and cities, so the state is still mostly small-town and country but is slowly getting more urban.

Fun story: "Joe, Montana"

• In 1993, the town of Ismay agreed to a publicity stunt and unofficially changed its name to "Joe, Montana" to honor NFL quarterback Joe Montana.
• The town used the joke name on signs and souvenirs for a while, which brought attention and visitors to a place that most people had never heard of before.

What this shows about Montana

• Montana has a few growing cities that feel busier and more crowded, but it also has many tiny towns where you might see more cows than people.
• From Billings' city lights to Ismay's one-street quiet, students can see how one state can include both "big city" and "everyone-knows-everyone" kinds of communities.

Largest and smallest counties by population

Montana's counties also range from busy and crowded to very quiet and tiny. This helps show how people are spread out across the state, not just in the cities.

Yellowstone County: most people

• Yellowstone County, where Billings is located, is the most populous county in Montana, with about 170,000-173,000 residents in the mid-2020s.
• This county has the feel of a regional hub: you find large stores, hospitals, colleges, and an airport, and many people from smaller towns drive there to shop or see a doctor.
• Even though it has the most people, Yellowstone County still isn't very dense compared with big-city counties in other states; it has roughly 60-70 people per square mile, so you can still reach open country quickly by driving a short distance.

Petroleum County: fewest people

Petroleum County, in central Montana, is the least populous county in the state, with only about 490-500 people total as of the 2020 census and recent estimates.

• The whole county has fewer people than many single middle schools, and its county seat, the town of Winnett, is a tiny community where it is common to recognize almost everyone you see in town.
• Because the county covers more than 1,600 square miles, there are well under one person per square mile on average, which means long drives between neighbors, lots of ranch land, and very dark, starry skies at night.

Largest and smallest counties by area

Montana's counties also vary a lot in how much land they cover. Some are bigger than whole states on the East Coast, while others are quite compact.

• Beaverhead County, in southwestern Montana, is the largest county by area, with about 5,540-5,570 square miles of land and water combined. That means one county is almost as big as the entire state of Connecticut, and it includes long valleys, tall mountains, ranches, and very few towns.
• Silver Bow County, where the city of Butte is located, is the smallest county by area in Montana, at about 718 square miles. Even though it is small in size, it holds an important historic mining city, so you can think of it as a compact county with one main urban center surrounded by hills and old mine sites.

Imagine: if you drove across Beaverhead County, it might take hours to get from one side to the other, passing mostly open country, but you could drive across Silver Bow County much faster and spend most of the time in or near Butte.

Updated: February 2, 2026