Bryce Canyon National Park is instantly recognizable by its vast natural amphitheaters filled with thousands of towering rock structures. These formations create a striking, otherworldly landscape that draws visitors globally. This massive collection of spires, fins, and arches, glowing in vibrant shades of pink, orange, and white, are known as hoodoos. Their presence results from a precise combination of rock type, climate, and erosional forces unique to this high-desert environment.
Defining the Hoodoo
A hoodoo is a tall, slender spire of rock that protrudes dramatically from an arid basin or badland. They are distinguished from other rock columns, like pinnacles or spires, by their irregular, variable thickness, often giving them a “totem pole-shaped body.” These formations can range in height from that of an average person to structures exceeding a ten-story building.
The characteristic shape results from differential erosion acting on layers of varying rock hardness. Many hoodoos feature a protective caprock, a layer of harder, more resistant rock like dolomite or siltstone, resting atop a softer column. This caprock acts like a shield, slowing the erosion of the material directly beneath it while surrounding unprotected rock is worn away more quickly. The final result is a column with a narrow neck and a wider, often mushroom-shaped top.
The Geological Recipe
The formation of a hoodoo begins with the fracturing of a large, flat plateau into vertical walls, known as fins. This initial cracking is caused by the uplift of the land, which creates near-vertical joint planes in the rock. Weathering forces then exploit these cracks, widening them into gullies and ravines.
The primary mechanism for erosion at Bryce Canyon is ice wedging, also called frost wedging. Water from rain or melting snow seeps into the vertical cracks and joints. When temperatures drop below freezing, the water expands by about nine percent, exerting tremendous pressure. This repeated expansion and contraction slowly pries the rock apart, widening the fractures.
As this process continues, sections of the fin become isolated, and openings are carved through the walls, creating “windows” or arches. Eventually, the top of the arch collapses, leaving behind the isolated, free-standing columns known as hoodoos. The combined action of ice wedging, which attacks the vertical joints, and chemical weathering from mildly acidic rainwater continuously sculpts the rock.
Why Bryce Canyon Is Unique
Bryce Canyon National Park hosts the world’s largest concentration of hoodoos due to a perfect convergence of environmental and geological factors. The rock layer that forms the hoodoos is the Claron Formation, a soft sedimentary rock composed primarily of limestone, dolostone, mudstone, and siltstone. This limestone is particularly susceptible to the carbonic acid naturally present in rainwater, which chemically dissolves the rock.
The vibrant colors of the hoodoos, ranging from pink and red to orange, are caused by iron oxides and other minerals within the Claron Formation. The presence of alternating hard and soft layers within this formation dictates the hoodoos’ variable thickness. The harder layers erode at a slower rate and often form the protective caps.
The park’s high elevation is the primary factor driving the rapid formation of its hoodoos. Bryce Canyon sits on the eastern edge of the Paunsaugunt Plateau, with the rim ranging from 8,000 to 9,000 feet above sea level. This altitude leads to a climate where the temperature frequently fluctuates above and below the freezing point. The area experiences over 170 to 200 freeze-thaw cycles annually, often within a single day, accelerating the ice wedging process. This rapid erosion carves the hoodoos at a pace of about two to four feet every 100 years.
Cultural Significance and Naming
The term “hoodoo” itself has roots that predate its geological application, often being associated with mystical or supernatural connotations. The word is believed to have originated as an alteration of “voodoo,” referring to a tradition of African American folk magic, or possibly from a Native American word. In the context of the rock formations, the name suggests a mysterious quality to the landscape.
Long before European settlers arrived, the Southern Paiute people inhabited the land and developed a rich mythology around the formations. The Paiute name for the area is Unka-timpe-wa-wince-pock-ich, translated as “red rocks standing like men in a bowl-shaped recess.” They called the hoodoos Anka-ku-was-a-wits, meaning “red painted faces.”
The Paiute legend explains the hoodoos as the petrified remains of the “Legend People,” or To-when-an-ung-wa, who were turned to stone by the spirit, Coyote. These ancient beings were punished for their misbehavior and transformed into the massive, silent stone figures that stand in the canyon amphitheaters today.