There are some pretty fun questions to ponder relating to geological terms: What is the difference between a pond and a lake? What is the difference between a river and a stream? What is the difference between a hill and a mountain?
This last question—the hill vs mountain debate—is of particular interest to hikers, ultramarathoners, mountain runners, fell runners, and backpackers.
When does a hill become a mountain?
What is the minimum height of a mountain in order for it to qualify as a mountain?
In this guide, we will look at the differences between hills vs mountains and see if there’s a clear answer to the great question, “When does a hill become a mountain?”
We’re going to look at:
- Hill vs Mountain: Similarities Between Hills and Mountains
- Hill vs Mountain: When Does A Hill Become A Mountain?
- How Much Taller Is a Mountain Than a Hill?
Let’s get started!
Hill vs Mountain: Similarities Between Hills and Mountains
When you’re running or hiking up an incline, the longer you’re ascending, the more certain you become that you’ve crossed the threshold from hill to mountain.
But is there an official height where a hill becomes a mountain? Is there a set mountain height? Does the grade or incline between a hill vs mountain differ?
Both hills and mountains are pieces of land that rise above the land that surrounds them, so they can be thought of as bumps on the surface of the Earth.
Hills and mountains typically offer a view from the top since they are higher than the land surrounding them.
However, while there is always a peak, or highest point, of a hill or mountain, there isn’t always a view.
Visibility depends on the tree cover at the top of the hill or mountain. If the hill is in a forest, for example, you won’t be able to see well through the trees to the land below.
Some hills are man-made, in which case they are termed mounds. For example, there’s a collection of well-known mounds made by Native American people in Hopewell Culture National Historical Park in the state of Ohio.
Mounds are relatively rare, so most hills and mountains are formed by the natural geological activity of the tectonic plates below.
Faulting can cause hills to form because the relationship to the plates changes and part of the crust can bump up into a range, ridge, or isolated bump.
These hills can eventually become mountains if the plates continue to bump together and drive the land upward.
The tallest mountain range in the world, the Himalayas, were once tiny hills formed by faulting (convergent plate boundary).
Glaciers, erosion, and volcanic activity can also cause and modify existing hills or mountains.
Hill vs Mountain: When Does A Hill Become A Mountain?
So, we’ve covered some of the similarities between a hill and a mountain, but what is the difference between a hill and a mountain?
Most people think of the mountain’s height as exceeding that of a hill, but at what point does a hill become a mountain? How tall is a mountain?
Interestingly, while most people intuitively distinguish hills and mountains by their height and grade, according to the United States Geological Survey (USGS), there actually isn’t an official difference between hills and mountains.
Prior to the mid-twentieth century, both the United Kingdom and the United States defined hills as summits less than 1,000 feet and mountains as summits equal to or greater than 1,000 feet.
However, both countries no longer maintain an official distinction of when a hill becomes a mountain.
According to National Geographic, “Hills are easier to climb than mountains. They are less steep and not as high.”
However, this comparison isn’t very specific, so it doesn’t clearly define when a hill becomes a mountain.
What constitutes what is “easy” to climb or “hard” to climb?
Do you have to have specialized gear, like trekking poles, crampons, or an ice axe, to climb a mountain, whereas you can walk, hike, or run up the hill with your regular athletic gear?
The degree of challenge involved in ascending a mountain or hill is really a subjective matter. What may be “hard“for one hiker or trekker might be “easy” for another, depending on fitness level, age, sex, experience, and altitude, among other factors.
Does this mean that a hill to one person might be a mountain to another? As can be seen, this vague definition does little to definitively differentiate a hill vs mountain.
Let’s turn to the dictionary definitions of hill vs mountain.
According to Merriam-Webster, a mountain is defined as “A landmass that projects conspicuously above its surroundings and is higher than a hill.”
However, the entry goes no further to say at what height a hill becomes a mountain.
Turning to the definition of a hill in the same dictionary, we find, “A usually rounded natural elevation of land lower than a mountain.”
Again, the comparative definition exists, but nowhere is there an exact distinction where one becomes the other.
The United Kingdom offers a bit more of an official “opinion” we can use for determining the difference between a hill and a mountain.
Geologists and the Oxford English Dictionary report that a mountain is at least 2,000 feet (or 610 meters) above sea level, while the government of the UK Government defines a mountain as having an elevation above 600 meters (1,969 ft).
In the absence of any other “official” designations, these figures may be the best we can do.
In many cases, hills and mountains are somewhat relative.
If you live in a really flat area, such as in the farmlands in the mid-western United States, the tiny bump in the land can feel like a mountain, even if it is a very small hill.
When you are running or hiking up a very steep trail along a hill or fell, it can feel like you are summiting Mount Everest.
The grade, or steepness, of the hill or mountain, greatly impacts how difficult it is to climb. Hills or mountains with a narrow base or that reach a high total height will be steeper and harder to climb than those with a wide base and gradual slope.
The conditions of the trail or terrain also significantly impact whether it will feel like you are climbing a hill or a mountain.
Let’s compare a theoretical mountain and hill, defined by the loose idea that a mountain is a hill taller than 2,000 feet.
By this definition, imagine a mountain where the base is at sea level, and the peak is only 2500 feet high. It has a wide, well-traveled trail to the summit. This should not be a difficult mountain to climb.
Comparatively, imagine a hill that is located at altitude where the base is 9000 feet above sea level. The hill is only 1800 feet high, yet the trail up the hill is extremely rocky and steep.
In this scenario, the hill would be harder to climb than the mountain.
Some geologists say that there can be high hills and low mountains, with the difference lying in the prominence of one over the other.
In this case, in terms of hills versus mountains, hills are less prominent based on their surrounding land, whereas a mountain juts up more conspicuously.
The prominence of a peak of either a hill or a mountain is defined as the elevation of the summit compared to its surrounding terrain.
This goes back to the concept of a mountain in one area appearing like a hill in another, depending on the surrounding topography.
How Much Taller Is a Mountain Than a Hill?
So, how tall is a mountain? It’s really not that clear.
The most complete and specific definition of a mountain comes from the United Nations Environment Programme.
Their topographical criteria for mountains are any of the following landmasses:
- An outcrop with a peak above 8,200 feet (2,500m).
- An outcrop with a peak between 4,900-8,200 feet (1,500-2,500m) with a slope of at least 2°.
- An outcrop with a peak between 3,300-4,900 feet (1,000-1,500m) with a slope greater than 5°.
- A local elevation range that rises at least 300m above the surrounding area within a 7 km radius.
Therefore, under these definitions of a mountain, even a hill that’s a mere 1,000 feet high can be called a mountain if the surrounding land is completely flat.
When it comes to differentiating between a hill vs mountain, most runners, hikers, and trekkers want to clear mountain status when they summit a challenging peak.
In the absence of a crystal clear distinction between a hill vs mountain, go for the glory: if it feels like a mountain, it is a mountain.
Enjoy the climb, enjoy the view, and enjoy the challenge.
Climbing hills and mountains are always quite challenging, but we have some tips and tricks to make your next trek feel a bit more achievable. If you would like to work on your uphill skills, check out our uphill running guide.