The River That Shapes Zion

A narrow river winds between towering red and cream-colored cliffs. High above the water, sunlight brightens layers of stone. This is Zion National Park in southwestern Utah, where rock and water tell a story that began long before people could see the canyon.

Much of Zion’s famous scenery is made of sandstone, rock formed from grains of sand pressed and cemented together. Millions of years ago, vast sand dunes covered this region. Over time, the buried dunes hardened into a thick layer of stone called Navajo Sandstone. Minerals helped give parts of the rock their red, orange, and pink colors.

The cliffs did not always stand high above a canyon. Forces inside Earth slowly raised the region, lifting layers of rock. Water then began cutting into them. The North Fork of the Virgin River, which flows through Zion Canyon, has been an important part of that work.

A river can wear away rock through erosion, the movement of material from one place to another. Flowing water carries sand, pebbles, and larger stones. As these pieces scrape and bump along the riverbed, they help grind away rock. During floods, faster, stronger water can carry more material downstream. Over a very long time, the river cut deeper into the raised landscape.