About the Grand Canyon

How Old is the Grand Canyon?

Colorado River Through Grand Canyon Rock Layers

The answer to the question “how old is the Grand Canyon” is a complicated one. Some estimates suggest the Grand Canyon is 5-6 million years old, but there’s more to calculating the age of the Grand Canyon than you might think. The canyon itself is made up of rock layers that are millions and, in some cases, billions of years old, with each layer representing a different geological time period. But the actual carving of the canyon and when it began to resemble the Grand Canyon as we know it today is a bit harder to pin down.

Even with the different tests and dating techniques available, geologists still haven’t managed to find a date they fully agree upon. It will take more time, research, and interpretation to figure out the Grand Canyon’s exact age, but in the meantime, let’s take a look at what we do know:

How old are the rocks that make up the Grand Canyon?

One thing geologists can agree on is the age of the layers of rock that make up the walls of the Grand Canyon. The youngest layer of the canyon—the Kaibab—is 270 million years old, while the oldest layers date back as far as 1.8 billion years.

Geology of the Grand Canyon Rock Layers
By The original uploader was Maveric149 at English Wikipedia. - Transferred from en.wikipedia to Commons., CC BY-SA 3.0

6 – Hermit, Coconino, Toroweap, and Kaibab – 270 to 280 million years old
5 – Supai Group – 285 to 315 million years old
4 – Temple Butte, Redwall, and Surprise Canyon – 320 to 385 million years old
3 – Tonto Group – 505 to 525 million years old
2 – Grand Canyon Supergroup – 740 million to 1.2 billion years old
1 – Vishnu Group – 1.6 to 1.8 billion years old

GRAND FACT: Grand Canyon National Park was established 101 years ago in 1919. This may seem like a long time ago, but it is actually quite recent if you consider the full timeline of the Grand Canyon.

How do geologists put a date on erosion?

The Grand Canyon was formed over a long period of time by erosion and downcutting. Downcutting is the process by which a river cuts down into and erodes the layers of rock to form a canyon. According to the National Park Service, there are “[s]everal factors [that] increase the amount of downcutting that happens in Grand Canyon: the Colorado River has a steep slope, a large volume, and flows through an arid climate.”

Knowing that the canyon was formed by erosion, you may be wondering how exactly scientists can put a date on the absence of something. It’s easy to tell the age of the rocks that make up the canyon, but figuring out how long some of them have been missing is a trickier process that involves complex scientific methods, including a fancy geochemical technique that measures the temperature of rocks: “The deeper a rock is buried, the warmer it is. When erosion removes the overlying rocks, as when a canyon forms, the rock is moved closer to the surface and cools down” (Witze, 2014).

The complicated process of these geochemical techniques and differing interpretations of the data is largely responsible for the debate over the age of the canyon. Different geologists don’t fully agree on what the results mean and some are even using different temperature ranges, which affects the results. Geologists Rebecca Flowers of the University of Colorado Boulder and Kenneth Farley of the California Institute of Technology in Pasadena, for example, determined their results “assum[ing] that the ground temperature at the surface is 25 degrees Celsius, whereas [another] team used a range of 10‒25 degrees” (Witze, 2014).

These differing methods are part of the reason the date range hasn’t been  , but while their results may be different, there is some general consensus about the age of the canyon overall.

When it became “Grand”

Research suggests that the Colorado River is estimated to have started eroding and downcutting the Grand Canyon at least 17 million years ago to as much as 70 million years ago, depending on who you ask and what section of the Grand Canyon you are asking about. But when did the downcutting “finish”?

The simple and most widely-accepted answer for when the Grand Canyon was eroded to its “current” recognizable state, and the one that’s included in the Trail of Time located at Grand Canyon National Park, is 6 million years ago. Some geologists, including Karlstrom—who has studied the Grand Canyon for over 30 years and helped develop the Trail of Time—suggest that “parts of the canyon could be tens of millions of years old”. In fact, Karlstrom estimates that some sections of the canyon are up to 70 million years old.

This doesn’t change the fact that the entire canyon, as it appears to us now, is much younger. So, even if there are sections of the canyon that were carved out 15-70 million years ago, they were not all connected by the Colorado River and did not form the Grand Canyon until a short 5-6 million years ago.

Grand Canyon Timeline

1.8 billion - 270 million years ago

The rock layers of the Grand Canyon were deposited.

1.8 billion - 270 million years ago

Water began downcutting to form sections of the Grand Canyon.

5-6 million years ago

The Grand Canyon as we know it today “finished” forming.

12,000+ years ago

Evidence of prehistoric humans passing through.

4,000 years ago

Evidence of earliest human habitation.

500 BCE-1,200 CE

Ancestral Pueblo people inhabited the area in and around the Grand Canyon.

Circa 1,000

The Paiute, Cerbat (ancestors of the Hualapai and Havasupai), and Navajo tribes began inhabiting the area.


Europeans first reached the Grand Canyon with help from Hopi guides.


The Grand Canyon railway was completed and many of the park’s currently operational buildings, such as Hopi House, Look-Out Studio, and Bright Angel Lodge were built during this time period.


The Grand Canyon was designated a National Monument by President Theodore Roosevelt.


The Havasupai regained a portion of their land that was taken when the Grand Canyon was designated a National Park.


The Grand Canyon is an awe-inspiring piece of landscape, slowly carved away over time by water and other rocks. To stand in or on the Grand Canyon is to be humbled by its awesome scale, irreproachable beauty, complicated history, and age. Whether it is 5 million years or 70 million years old, the Canyon has certainly been here a lot longer than us and is worth seeing for yourself at least once.

Learn more about the Grand Canyon


About Ria Borja

Ria is a Customer Experience Manager at Canyon Tours and an avid lover of the outdoors. When she isn't helping other travelers check destinations and dream vacations off their bucket lists, she's busy exploring the Southwest. Her favorite place to visit is (unsurprisingly!) the Grand Canyon.