Millions of Years of Erosion At Work
The majestic hill looms above the road at a height of 900 feet, mesmerizing people with its patterning. The checkerboard-like pattern is the result of millions of years of rock erosion processes. The cracks can be found in Navajo Sandstone, which is a prominent formation in the cliffs of Zion. The thickness at some places can be more than 2,000 feet, and the sandstone is the result of ancient sand dunes being compressed into rock.
Nature Used Two Distinct Modes of Rock Weathering to Form the Pattern
The vertical lines in the sandstone have been determined as the result of contraction and expansion. This happens when the rock is heated by the sun during the day and cooled dramatically at night. The tiny structural fissures in the bedrock have also helped form the vertical lines in the rock, and the cycle was further boosted by water penetration from melted snow and rain. As for the horizontal lines, those are the result of wind erosion. The wind carries with it sand and acts as a natural sandblasting machine. This reveals the original sedimentary dune structures called cross-bedding. Because these distinct modes of rock weathering combine together, the north face of the mountain has formed to be the characteristic checkerboard pattern.
The name Checkerboard Mountain was given to the area by Preston Patraw in the 1930s, who was the then-superintendent of Zion. Before that, it was commonly referred to as Rock Candy Mountain. Checkerboard Mesa is not the only example of this kind of weathering pattern, but it being near Highway 9 makes it the best-known one. The geologic processes that formed the pattern are still ongoing, and in time, the massive monoliths will inevitably break down and go back to being great dunes.