The term "Grand Staircase" refers to a sequence of sedimentary rock layers that form a massive "staircase" between Bryce Canyon and Grand Canyon. Each canyon's cliff edge acts as a giant step displaying the earth's geologic history and its layers. As one moves down the geologic column, each successive rock layer is older than the previous one. The oldest exposed formation in Bryce Canyon is the youngest remaining layer in Zion Canyon. Likewise, the floor of Zion Canyon is Kaibab Formation, which is the same formation one stands on at the Grand Canyon's rim. As one stands at the South Rim looking into the depths of the grandest canyon of them all, one is witnessing some 2 billion years of geologic history.

Your Guide to the National Parks by Michael J. Oswald

The soft pink Claron Formation of Bryce Canyon succumbs quickly to monsoon floods and flashfloods, and current exposures are only remnants of its former extent. Geologists believe the layers of Bryce once covered what is now Zion National Park and that Zion's layers once covered Grand Canyon. Hypothetically, the waters of Bryce could cut straight down and dissolve the Pink Cliffs, incise a Zion Canyon through now-hidden layers, and then chisel a Grand Canyon; of course, this might take 50 million years or so. These three "canyons" differ in size because Grand Canyon is cut by the mighty Colorado River, Zion by the steady Virgin River, and Bryce by the fickle headwaters of the Paria River.

Bryce Canyon: The Desert's Hoodoo Heart by Greer Chesher

The pink and red hue of rocks is created by oxidation of iron in mud and silt. This results in the presence of hematite, the mineral form of iron(III) oxide (Fe₂O₃).

Most trees at this elevation are white fir and Douglas-fir. In contrast to open groves of ponderosa pine on the lower plateau, trees here grow in dense stands and deep shade. Their shadows prolong moisture-giving snow banks and steal sunlight from competing species on the forest floor.

White fir (Abies concolor) needles sprout single instead of clusters. Cones and needles grow upright on the branch.

Douglas-fir (Pseudotsuga menziesii), not a true fir, has cones with distinctive three-pronged bracts that grow from beneath the cone scales.

The park description

These trees grow at remarkably high elevations, in some cases appearing only at elevations higher than that of all other trees. This pine of the desert mountains is widely known as the longest-lived tree in the world; hundreds of individual trees are known to exceed ages of 3,000 years, and the oldest tree known is more than 5,000 years old. Researchers studying the bristlecone pine DNA have learned that these trees have unique adaptations to long life. They also live in a very cold, dry environment that does not support the pests and diseases that afflict trees in warmer, wetter sites. In addition, they live in forests that are essentially fireproof because the trees are widely spaced and there is no undergrowth. Traditionally, the main hazard to bristlecones was lightning strikes, which can kill individual trees, but now whole stands are threatened by climate change. This is forcing them to migrate upward to cooler elevations. For a tree that grows on mountaintops, a warming climate is a death sentence.

Trees of Western North America by Richard Spellenberg, Christopher J. Earle, and Gil Nelson

Bristlecones thrive where few other plants can grow. At the windiest point of the trail, on bare rocky ground, this bristlecone has lasted more than 1,600 years.

Bristlecone pines can survive prolonged drought. When branches and portions of the trunk appear dead, other limbs may function as the main trunk. This bristlecone's trunk has been dead a long time, while a surviving branch has become the new tree.

The park description

The white fir (Abies concolor) is a native tree. Its needles are 2-ranked, 1.5-6 cm long, 2-3 mm wide, flexible, flattened, with a usually rounded apex. Their upper surface is sometimes grooved and the lower surface has two parallel bands of stomata. The bark is gray, thin, and smooth. It thickens with age and breaks into deep longitudinal furrows, often revealing the yellowish inner bark, variably corky.

Trees of Western North America by Richard Spellenberg, Christopher J. Earle, and Gil Nelson

Two western junipers, the common juniper (Juniperus communis) and the creeping juniper (Juniperus horizontalis), grow as low, mat-forming shrubs, seldom more than 1 m tall. The common juniper is widespread in mountains and has only needle-like leaves. The creeping juniper occurs in mountains and woodlands of the Rockies north from Wyoming, and in boreal western Canada, and has scale-like leaves.

Trees of Western North America by Richard Spellenberg, Christopher J. Earle, and Gil Nelson

The Uinta chipmunk (Eutamias umbrinus) is the most common of the three chipmunk species that inhabit Bryce Canyon and, with careful observation, it is possible to distinguish the Uinta chipmunk from the other two Bryce Canyon species. The Uinta chipmunk has wide and distinct dark brown or black stripes, whereas the least chipmunk's (Tamias minimus) dark stripes are narrow. The cliff chipmunk (Tamias dorsalis) is the least colorful of the three species. It lacks any orange coloration and is mainly gray with faint, thin, black and white stripes. Bryce Canyon is also home to the golden-mantled ground squirrel (Spermophilus lateralis), often described as a "big fat chipmunk." This type of ground squirrel has similar markings to that of a chipmunk but with one major difference. All of the western chipmunks have a dark eye-line stripe across their faces, as if wearing a Zorro mask. No ground squirrels in North America have any facial stripes.

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Beauty is only skin deep, but some advanced science doesn't need to go deeper: Mallarino et al. (2016) Developmental mechanisms of stripe patterns in rodents. Nature 539: 518–523. This article focuses on a transcription factor, but the spatial aspect of the process is likely to be based on a reaction-diffusion system (see, for example, Watanabe and Kondo (2015) Is pigment patterning in fish skin determined by the Turing mechanism? Trends in Genetics 31: 88-96).

At Bryce Canyon, weathering can alter huge rocks within a human lifetime. Rain and frost-wedging carve these stones into curious shapes, including the Queen Victoria hoodoo, which was named for a statue in London, England. If you use your imagination, you might see the hoodoo queen riding an animal.

The park description