The Navajo Sandstone was deposited between 192 and 178 million years ago of a sand sea that stretched from AZ to WY with dunes that towered a 1000 ft high. (from Geology Underfoot in Northern AZ)

Navajo Sandstone is a geologic formation in the Glen Canyon Group that is spread across the U.S. states of northern Arizona, northwest Colorado, Nevada, and Utah (the unit is not part of a group in Nevada). It is located in the Colorado Plateau province of the United States. This rock formation is particularly prominent in southern Utah, where it forms the main attractions of a number of national parks and monuments including Zion National Park, Capitol Reef National Park, the Grand Staircase-Escalante National Monument, and Canyonlands National Park. Navajo Sandstone frequently occurs above the Kayenta Formation and Wingate Sandstone (all three formations are in the same group). Together, these three formations can result in immense vertical cliffs of 2,000 feet (610 m) or more. Atop the cliffs, Navajo Sandstone often appears as massive rounded domes and bluffs that are generally white in color.

Navajo Sandstone frequently occurs as spectacular cliffs, cuestas, domes, and bluffs rising from the desert floor. It can be distinguished from adjacent Jurassic sandstones by its white to light pink color, meter-scale cross-bedding, and distinctive rounded weathering.

The wide range of colors, i.e. crimson, vermillion, orange, salmon, peach, pink, gold, yellow, and white exhibited by the Navajo Sandstone reflect a long history of alteration of it by groundwater and other subsurface fluids over the last 190 million years. The different colors, except for white, are caused by the presence of varying mixtures and amounts of hematite, goethite, and limonite filling the pore space within the quartz sand comprising the Navajo Sandstone.
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See the White Cliffs. And the bottom of the profile at the Grand Staircase