Antelope Canyon

Long, long ago, this land was a desert of sand dunes.

The sand slowly turned into rock. Then rainwater rushed through narrow gaps in the rock. Bit by bit, it carved this narrow canyon.

The walls of Antelope Canyon are Navajo Sandstone. This rock formed from large sand dunes blown by the wind, in a desert sea of sand.

Much later, water carved the canyon. When it rains, water runs from a wide area above into the narrow passages, picking up speed and sand as it goes. Over time the rushing water wore the passages deeper and smoothed their edges into flowing, wavy shapes. Weathering, such as freezing and thawing, helped too. This carving is still going on today.

The European Geosciences Union (EGU) describes Antelope Canyon as eroded into the Navajo Sandstone mainly by flash flooding and secondarily by other sub-aerial processes, physical weathering such as freeze-thaw, exfoliation and salt crystallization. Rainwater gathers in the extensive basin above the slot sections and gains speed and sand as it rushes into the narrow passages, deepening the corridors and rounding hard edges into the characteristic flowing shapes.

The Navajo Sandstone was laid down as large aeolian (wind-blown) dunes in an erg, a sea of sand. Its exact age is debated: with no age-diagnostic fossils, dates range from the Triassic to the early Jurassic, between about 250 and 175 million years ago.

Long ago, herds of antelope ran free here. That is how the canyon got its English name.

The canyon is on the land of the Navajo people. Navajo guides show visitors the way.

The Navajo Nation's park says that long ago, herds of pronghorn antelope roamed freely in the canyon, which explains its English name. Local Navajo people say the canyon and the LeChee area were once places where cattle grazed in winter.

The canyon is on Navajo Nation land, and Navajo law applies there. The park says that entering a place like Antelope Canyon was, for older Navajo people, something to do with respect: they would probably pause first, to be in the right frame of mind.

Per Lake Powell Navajo Tribal Park: herds of pronghorn antelope once roamed freely in the canyon, explaining the English name; it is not known exactly when people first discovered it; and, according to local Navajos, the canyon and the LeChee area were winter grazing places for cattle. The park writes that older Navajos would pause before entering, to be in the right frame of mind and to show respect.

Navajo Nation laws (Title 19 of the Navajo Nation Code) and the tribal parks' rules apply. The National Park Service's neighboring Glen Canyon National Recreation Area points visitors to the tribal park and its approved tour providers.

The canyon is narrow and deep.

In this picture, light comes in through a narrow gap at the top. The rock walls look bright orange. A beam of light shines all the way down to the floor.

In this photo, light comes in through the thin gap at the top of the canyon. A shaft of light shines down from the opening and lands as a bright patch on the sandy floor, while the curving sandstone walls around it glow in shades of orange.

The smooth, swirling walls show the shapes carved by the water. So many people come to see them that the Navajo Nation's park does not give out photography or filming permits for Upper and Lower Antelope Canyon.

The flowing wall shapes are the record of flood erosion that deepened the corridors and rounded their edges (EGU). In the photo, light falls from the narrow slot above in a visible shaft onto the floor, and the sandstone walls curve around it.

The tribal park says that because of the very high number of visitors it issues no photography or filming permits for Upper and Lower Antelope Canyon, and since 1 May 2011 visits inside Upper Antelope Canyon have had a two-hour limit.

You can only visit with a Navajo guide.

When it rains, water can rush into the canyon fast. The guides watch the weather and keep visitors safe.

A guided tour is the only way into Upper and Lower Antelope Canyon. The tour companies are approved by the Navajo Nation, and the guides know the canyon and its history. There is an entry fee as well as the tour price, dogs are not allowed, and the park is closed on major holidays.

Slot canyons can flood suddenly. The National Park Service warns visitors never to enter canyons when a flash flood is possible, and the EGU notes that this risk is one reason the canyon can only be visited with a guide.

Entry to Upper and Lower Antelope Canyon is by Navajo Nation-approved guided tour only, with a per-person entry fee separate from the tour price; dogs are prohibited at all Navajo tribal parks; the park closes on major holidays; backcountry areas need a permit, and visitors enter at their own risk.

Flash floods are a hazard here: the NPS advises against entering washes or canyons when a flash flood is possible, and the EGU links the elevated flash-flood risk to the guided-tour rule. Lower Antelope involves narrow passages and stairs.