Stories carved by the Colorado River
The missing pieces of the Grand Canyon: 10 incredible facts
Image: jesus esteban
The Grand Canyon is bigger than Rhode Island. It's deeper than four Empire State Buildings stacked end to end. Its rocks are older than dinosaurs. But those stats alone don’t quite capture its immensity — and are hardly the most shocking. There are nuclear shelters, hidden villages, and billion-year mysteries involved. Read on to learn 10 lesser-known facts about the Grand Canyon.
1
There's an unexplained billion-year gap
Look closely at the canyon walls, and you'll notice something strange: a clean, sharp line where ancient rock simply stops, and a much younger layer begins directly above it.
This geological puzzle is called the "Great Unconformity," and it represents over a billion years of rock layers that are simply absent , as though that stretch of time never happened. In some spots, rock dated 1.8 billion years old sits directly beneath rock that is only 520 million years old. Where did the missing billion years go?
The leading theory involves the violent breakup of an ancient supercontinent, but scientists are still piecing it together.
2
During the Cold War, it hid a nuclear fallout shelter
During the Cuban Missile Crisis in 1962, the U.S. government converted part of the Grand Canyon Caverns into a fallout shelter. This dry cave system, more than 200 feet underground, was stocked with enough food and water to sustain 2,000 people. Naturally, it was never occupied, and the supplies were never used.
The caverns have since been transformed into a tourist attraction, with organized tours winding through the same underground chambers that were once intended as a refuge from nuclear war. You can even book a night's stay there.
3
The Federal Aviation Administration was founded after a crash over the canyon
In 1956, two commercial passenger planes collided in midair over the eastern Grand Canyon, killing all 128 people on board both crafts. Rescue teams struggled to reach the wreckage deep inside the canyon, and the extreme heat of the crash had caused the planes' aluminum to fuse with the bedrock. There were no survivors.
The disaster exposed a terrifying truth: the U.S. air traffic control system was dangerously outdated, relying on pilots' visual estimates and rough guesswork from controllers , with no way to separate fast-moving aircraft from slow ones, or instrument-flying planes from those navigating by sight. Congress responded by passing legislation that created both the Federal Aviation Administration (FAA) and the National Transportation Safety Board.
4
A hoax suggested that an Egyptian civilization had lived there
In 1909, the Arizona Gazette reported that an explorer named G. E. Kinkaid had discovered a vast underground citadel inside the canyon, filled with artifacts linked to ancient Egyptian civilization. He even claimed the expedition had been funded by the Smithsonian.
This story described hieroglyphics on the walls, mummies in the chambers, and relics pointing to a direct connection with the Egypt of the pharaohs. It was incredibly detailed, and it was, of course, a hoax. No evidence for any of Kinkaid's claims ever surfaced.
5
Less than 100 people have ever hiked its full length
Among the few people who have completed the through-hike of the Grand Canyon is Jen Hogan, the first woman to accomplish it, finishing her journey in 2021–2022.
It’s a full 800-mile length below the rim. The route involves extreme heat, flash floods, near-impassable areas, and stretches with no water or trail whatsoever. Around 60 or 70 people have reportedly accomplished it. This makes it one of the most exclusive feats on Earth.
6
The Grand Canyon's rocks predate dinosaurs entirely
Visitors scanning the canyon walls for fossils are often surprised to learn they won't find any dinosaur bones here. The rock layers of the Grand Canyon are simply older than dinosaurs. This fact alone can be shocking: staring at its walls means staring at marine fossils from as far back as 1.2 billion years ago. Some of its caves hold the remains of ancient mammals. The canyon is a window into a world that existed long before the dinosaurs, when the land that is now Arizona lay beneath a shallow sea.
7
The park is bigger than Rhode Island
Numbers alone rarely capture the Grand Canyon's scale, so here's a different approach. Rhode Island covers about 1,214 square miles, and the Grand Canyon National Park spans 1,904 square miles.
The canyon's depth exceeds four Empire State Buildings (which is 1,454 feet) stacked on top of one another. That’s 6,093 feet at its deepest point.
8
But it's not the deepest canyon on Earth
For all its grandeur, the Grand Canyon does not hold the depth record. Pictured above, Yarlung Tsangpo Grand Canyon in Tibet, China, plunges to 17,567 feet, which is nearly three times deeper. Carved by the Yarlung Tsangpo River as it cuts through the eastern Himalayas, that canyon is so remote and extreme that it remained largely uncharted until the late 20th century.
9
It is home to a pink rattlesnake found nowhere else on Earth
The Grand Canyon Pink Rattlesnake has a pinkish-red coloring that matches the canyon's own distinctive rock walls so closely that it's nearly invisible. It is found nowhere else in the world. Officially classified as Crotalus oreganus abyssus , it has darker diamond-shaped markings along its back that deepen the camouflage further.
10
There's a village at the bottom: Supai Village
For over 1,000 years, the remote village of Supai has been home to the Havasupai Tribe, the People of the Blue-Green Waters. It is located eight miles below the rim of the Grand Canyon.
The U.S. Department of Agriculture has called it the most remote community in the contiguous United States, and it has no automobiles and no road access. The only ways in are on foot, by mule, or by helicopter. It is also the only place in the United States where the postal service still delivers mail by mule train.
