The United States Geological Survey (USGS) says there’s no one way to tell a mountain from a hill. Hills are usually lower and have a soft, rounded shape with gentle slopes. Mountains, on the other hand, are taller, with steep sides, a clear top, and are over 2,000 feet high.
Many people have argued about what makes a hill a mountain. There’s no official rule. What makes something a hill or a mountain depends on the area, its geology, and how people see it. In the UK, a mountain is over 600 meters tall, but the USGS says height doesn’t matter.
Defining Hills and Mountains
It can be tricky to tell hills from mountains, as there’s no clear rule. Yet, some traits help us tell them apart.
Hills are like natural hills or bumps on the earth, often round and gently sloping. They’re usually under 2,000 feet tall and don’t have a clear top. Mountains, however, have a sharp rise, are at least 2,000 feet high, and have a clear top. Mountains often come in ranges, while hills stand alone.
The U.S. Board on Geographic Names once said a hill was under 1,000 feet tall. But they stopped using this rule in the 1970s. Now, there’s no official way to tell hills from mountains. Local ways of seeing things matter more.
In places like the Southwest U.S., mountains have their own plants and animals. This affects the local weather and life zones. Hills, seen as worn-down mountains, show how different rocks and soils shape the land.
But hills and mountains can share traits, making it hard to define them strictly. What people think and local stories also play a big part in how we see these landforms.
Formation and Evolution
Hills and mountains come from geological processes over long periods. Hills often form from erosion of bigger landforms. Mountains, however, come from tectonic activity, like the Earth’s crust uplifting and folding.
Volcanic mountains form from tectonic plate movements that create volcanoes. Composite cones have steep slopes of 33°-40° because of the erupted materials’ high viscosity. Shield volcanoes, like Mauna Loa, have gentler slopes of 4°-6° because their erupted materials are less viscous.
Fold mountains happen when tectonic plates collide or one plate goes under another, causing the Earth’s surface to fold. Block mountains come from fault blocks that rise or tilt, with higher areas called horsts and lower areas called grabens. Some mountains, like the Scandinavian Mountains, don’t have a clear explanation for how they formed.
The making of mountains is linked to plate tectonics. This includes folding, faulting, volcanic activity, and changes in the Earth’s rocks. These forces can turn small hills into huge mountain ranges over millions of years. This process makes it hard to tell hills and mountains apart.
What is the difference between a hill and a mountain?
There’s no one way to define hills versus mountains, but some differences stand out. Hills are usually lower, often under 2,000 feet tall, with slopes that are gentler. Mountains, on the other hand, are taller and have steep, sharp slopes. They also have a clear summit, unlike hills which are more rounded.
Mountains often have unique features like cliffs, ridges, and glaciers. Hills are smoother and don’t have these distinct features. But, some mountains, like the Poconos in Pennsylvania, look more like hills due to erosion over time.
The line between hills and mountains can be blurry and depends on where you are. The British Ordnance Survey says a mountain is over 1,000 feet tall. In the U.S., mountains used to be anything over 1,000 feet tall until the 1970s.
At the end of the day, the main difference is height. Mountains are taller and have more dramatic features than hills, which are more gradual and less tall.
Height and Topography
One key difference between hills and mountains is their height and shape. Mountains are usually over 2,000 feet tall and have a sharp rise in the land. Hills are lower, under 2,000 feet, and have a gentle slope.
This height difference changes the landscape and what activities are possible. Hills are easier to climb, making them good for casual walks. Mountains are tougher due to their steep sides and high elevations. Yet, these rules don’t always apply, as there are exceptions.
The US started mapping hills and mountains with topographic maps in 1879 by the U.S. Geological Survey (USGS). By the 1930s, aerial photos made these maps more precise. Today, the USGS updates maps every three years with satellites and drones, moving away from human surveys.
Now, not just governments but also companies like Google Maps make these maps. Google uses data from the USGS and satellites, focusing on LiDAR readings. This makes their maps very detailed.
On topographic maps, contour lines show different heights. The lines are closer together where the slope is steep, and farther apart where it’s gentle. These lines help show the shape of the earth’s surface.
Geological Features and Naming
Understanding the geological features and naming conventions can help tell hills and mountains apart. Mountains usually get names like “Mount” or “Peak” because of their tall, clear tops. Hills, though, might not have official names and are often just called a “hill” or a local spot.
Mountains come from tectonic activity, like the Earth’s crust moving and folding. Hills, however, come from erosion, where forces like wind and water shape the land. This difference in how they form affects their looks, with mountains being rough and hills being smoother.
The Flint Hills in Kansas are a great example. They stretch from 30 to 100 miles wide and are made of limestone and shale from 280 million years ago. The limestone makes hillsides with terraces, while the shale erodes faster, creating unique hills.
In Arkansas, the Ozark and Ouachita Mountains formed about 500 million years ago, when the area was covered in oceans. Rocks like limestone, shale, and sandstone have been shaped by geological processes, making hills, valleys, and mountains.
| Geological Feature | Description |
|---|---|
| Basalt | A fine-grained, black-colored igneous rock commonly formed from a runny type of lava in Hawaii. |
| Abyssal Plain | Usually flat and 2 to 6 km deep with occasional volcanic mountains and mid-ocean ridges. |
| Batholith | Large intrusions of granite, formed deep beneath the surface where rock cooled slowly. |
| Calcite | The main component of limestone, which fizzes with dilute acid. |
| Cementation | The process where sediment grains are cemented together by minerals deposited from groundwater, turning sediments into rock. |
Human Influences and Uses
Hills and mountains have always been key to human life. They offer both challenges and chances for people throughout history.
Many cities sit on hills because they’re easier to build on. Hills also helped protect ancient cities like Rome, built on seven hills. Mountains are harder to settle but are prized for their beauty, fun activities, and resources.
Humans have built roads, railways, and resorts to reach and change hills and mountains. But how we affect these places can be very different. Mountains give us wood, land for animals, water, and clean air. Yet, mining, energy making, and tourism can harm mountain life.
Climate change hits mountains hard, melting glaciers and changing weather. This hurts the variety of life, affecting all living things. It also messes with the important work of tiny organisms in the soil.
We need to think about how we use hills and mountains. It’s important to balance our needs with protecting these vital places.
Geographical Exceptions
While hills and mountains have clear differences, there are many exceptions. For example, the Black Hills in South Dakota are a small mountain range but called “hills” because they’re not very tall and have soft peaks. The Baraboo Hills in Wisconsin are seen as a mountain range, even though no peak is high enough to be called a mountain.
These examples show how local geography, culture, and tradition affect how we see hills and mountains. Spain, for instance, is very mountainous, with many types of mountains. It has folded mountains like the Mulhacén and Veleta, and domes like El Yelmo near Manzanares del Real.
Knowing about these exceptions helps us understand the wide range of Earth’s landforms better. The way we classify hills and mountains changes a lot from place to place. This reflects the unique geological past and cultural views of each area.
Types of Hills
Hills come in many shapes, each made by different geological forces. Drumlins are long, smooth hills made by glaciers moving. They are found where ice sheets once covered the land. Buttes are tall, steep hills with flat tops. They form when erosion takes away the land around them.
Tors are special hills with rock structures on top. They are shaped by weather and erosion over time. Hills also include pingos, which are earth-covered ice mounds, and puys, which are volcanic hills shaped like cones.
There are many kinds of hills, showing how complex they can be. They are shaped by various geological events, like glaciers moving or volcanoes erupting. This shows how the Earth’s surface is always changing.
| Hill Type | Description | Formation Process |
|---|---|---|
| Drumlin | Elongated, streamlined hills | Glacial movement |
| Butte | Isolated, steep-sided hills with flat tops | Erosion |
| Tor | Distinctive rock formations atop hills | Weathering and erosion |
| Pingo | Mounds of earth-covered ice | Freezing of groundwater |
| Puy | Cone-shaped, volcanic hills | Volcanic activity |
Scenic and Recreational Value
Hills and mountains are loved for their beauty and fun activities. Hills have gentle slopes that make them great for enjoying views. They’re perfect for hiking, picnics, and other outdoor fun. Mountains, with their stunning views, offer activities like rock climbing and skiing.
People visit hills and mountains for their beauty and adventure. Whether it’s the Midwest hills or the Rockies, these places amaze and inspire us. They’re key in the tourism and outdoor activities in the U.S.
The National Park Service and Bureau of Land Management protect these areas. People go to hills and mountains for amazing views and adventures. Their beauty and fun value show how important they are to us all.