Holly Strand, Author at Wild About Utah

March 17, 2011May 9, 2016

Owl Vision

Barn owl sleeping in a tree, Photo Copyright 2010 Mike Fish — Barn Owl Sleeping in a Tree
Copyright © 2010 Mike Fish

Hi I’m Holly Strand.

Great-horned and other nocturnal owls have phenomenal nighttime vision. In some respects—they see much better by night than we can by the light of the sun. The visual acuity of owls springs from a number of interesting adaptations.

Of course you’ve noticed that owls have big eyes. If our eyes were in the same proportion to the size of our head, they would be the size of grapefruits! Large owl corneas and lenses help maximize the amount of light received by the retina.

There are two types of photo receptors in the retina. Cones operate in bright light and give fine detail and color vision. Rods work with much less light but compromise somewhat on detail and color. Owl eyes contain considerably more rods than cones while the eyes of daytime animals–like us –contain many more cones than rods.

Great Horned Owl, Photo Copyright 2010 Mike Fish — Great Horned Owl
Copyright © 2010 Mike Fish

Owls –and other nocturnal creatures—have a mirror-like structure behind the retina called a tapetum. Light passes through the rods and cones, strikes the tapetum and is reflected back through the eye to the light source. The tapetum ensures that any light unabsorbed by receptor cells is reflected back through the eye. This gives the receptor cells a second chance at stimulating the rods.

Owls, like most predators, have eyes positioned forward on the face and looking in the same direction. The resulting binocular vision gives the owl a three dimensional perspective. By accurately sensing depth, the owl can zero in on a tasty little mouse scurrying across a field and make adjustments on the wing as it closes in for a kill. To help triangulate even more precisely, owls will often bob or weave their heads to get several viewpoints of an object.

Finally, because of their unique eye structure, owls cannot move their eyes within the sockets. No worries! The owl just moves its whole head instead. On an exceptionally mobile neck, an owl head can rotate at least 270 degrees from side to side and 90 degrees up and down.

For some great pictures of owls and their enigmatic eyes, go to www.wildaboututah.org

For Wild About Utah, I’m Holly Strand.

Credits:

Text: Holly Strand

Sources & Additional Reading:

Cornell Lab of Ornithology. https://www.birds.cornell.edu/

Utah Division of Wildlife Resources. Utah Conservation Data Center. https://dwrcdc.nr.utah.gov/ucdc/

Scholz, Floyd. 2001. Owls. Mechanicsburg PA: Stackpole Books

Sparks, John and Tony Soper. 1989. Owls: Their Natural and Unnatural History. NY: Facts on File.

February 17, 2011January 9, 2023

The Sistine Chapel in Utah

Utah is famous for the beautiful and mysterious rock art found on its colorful canyon walls.

There are two main types of rock art. A petroglyph is an image that is pecked, incised, or scratched into rock. Petroglyphs are often found on rock surfaces coated with desert varnish. The dark stained varnish provides high contrast as the image is carved into the lighter underlying stone.

Pictographs, however, are painted onto rather than carved into a rock surface. Mineral pigments such as hematite, limonite, azurite, and gypsum were used to produce long lasting liquid and solid paints. Paint was applied with brushes, fingertips or hands, with fiber wads and even by spraying or blowing paint. It’s possible that vegetable dyes were also used by ancient artists but these would have been washed away without leaving a trace.

Archaeologists classify ancient rock art into different styles according to image content, drawing techniques, location, and the relationships between various picture elements. The so-called Barrier Canyon Style is well-known in eastern Utah where its greatest level of expression is found.

The Barrier Canyon Style features human-like figures with a supernatural appearance. Torso lengths are exaggerated and shaped like mummys or bottles. Heads may have horns, rabbitlike ears or antennalike projections. Eyes of the figures are often round and staring. Hands, if present, may be holding plant-like images or snakes. Aside from the human-like figures, birds, canines, bighorn sheep, and rabbits are also common in Barrier Canyon Style compositions.

Cultural affiliations of the Barrier Canyon Style artists are still not fully understood. But most archeaologists agree that the artists were part of small bands of nomadic people who roamed the Colorado Plateau between 7500 BC and 300 AD.

Perhaps the best place to view the Barrier Canyon style is in the Great Gallery in Horseshoe Canyon near Canyonlands National Park. The Great Gallery features a 300 feet long mural with over 60 figures. David Sucec (pronounced Soosek)–who is coordinating an effort to photograph and record all Barrier Canyon Style rock art–calls the Great Gallery ‘Utah’s Sistine Chapel.’

So far over 230 different sites featuring Barrier Canyon Style rock art have been discovered. In Utah, look for them in the Book Cliffs area, the San Rafael Swell, around Moab and in Canyonlands National Park.

Thanks to the Red Cliffs Lodge in Moab, Utah for supporting research and development of this Wild About Utah topic.

For Wild About Utah, I’m Holly Strand.

Credits:

Images: Courtesy & Copyright David Sucec
Text: Holly Strand, Stokes Nature Center

Sources & Additional Reading:

BCSProject. https://www.bcsproject.org/about.html

Cole, Sally. 1990. Legacy on Stone: Rock Art of the Colorado Plateau and Four Corners Region. Boulder, CO: Johnson Printing

Repanshek, Kurt. Traces of a Lost People. 2005. Smithsonian magazine. March 2005. https://www.smithsonianmag.com/people-places/lost.html

Schaafsma, Polly. The Rock Art of Utah. 1971, Third Printing 1987, Papers of the Peabody Museum of Archaeology and Ethnology Vol. 65, paper, 169 pp. https://www.amazon.com/Rock-Art-Utah-Polly-Schaafsma/dp/0874804353

Take the Pledge to Protect the Past, Utah State Historical Preservation Office, Department of Cultural & Community Engagement, State of Utah, https://ushpo.utah.gov/shpo/upan/

January 27, 2011August 19, 2025

Utah, the Red State

Hi, I’m Holly Strand for Wild About Utah

Straddling the four corners region is a massive geologic province known as the Colorado Plateau. Varying from 5 to 10,000 feet in elevation the region covers an area even larger than Utah, and is composed of thick horizontal layers of sedimentary rock. Wind and water have whittled Plateau rock into dramatic cliffs and steps as well as fanciful domes, towers, turrets, and arches. A predominance of red bed deposits in the central area of the Plateau has prompted the nickname “red rock country.”

So what’s behind these spectacular red hues? The color of rock is primarily influenced by trace minerals. The red, brown, and yellow colors so prevalent here result from the presence of oxidized iron–that is iron that has undergone a chemical reaction upon exposure to air or oxygenated water. The iron oxides released from this process form a coating on the surface of the rock or rock grains containing the iron.

Utah, the Red State: Entrada sandstone is responsible for some of the reddish rock found in Arches National Park. Photo Courtesy USGS — Entrada sandstone is responsible
for some of the reddish rock found
in Arches National Park.
Courtesy USGS

Just think of what happens to a nail when you leave it outside. Upon prolonged exposure, the iron in the nail oxidizes and rust is formed as a coating on the surface of the nail. So basically what we have in red rock country is a lot of rusting sandstones and shales. Hematite is an especially common mineral form of iron oxide in Utah, the name coming from the Greek word “heama” or red blood. It only takes a tiny bit of hematite make a lot of red rock.

Certain rock formations in Utah are particularly well-known for their beautiful reddish colors. The Permian Period gave us Organ Rock shale which caps the buttes and pinnacles of Monument Valley. The deep ruddy browns of the Moenkopi formation were formed in the Triassic. In the early Jurassic, eastern Utah was a vast sea of sand with wind-blown dunes. These dunes became the red bed deposits of the Wingate Formation which today forms massive vertical cliffs. Entrada sandstone, from the late Jurassic, forms the spectacular red, slickrock around Moab.

Reddish brown Moenkopi Formation in Capitol Reef National Park, Photo Courtesy USGS — Reddish brown Moenkopi Formation
in Capitol Reef National Park.
Courtesy USGS

So now you know what I’m thinking of when I hear Utah referred to as a Red State. I’m picturing the extraordinary splendor of the red, orange and rust- brown rocks that help to form the massive geologic layer cake in the south and east of our state.

For Wild About Utah I’m Holly Strand.

Utah, the Red State-Credits:

Photos: Courtesy National Park Service, https://www.nps.gov/brca/ and

United States Geological Survey (USGS), https://www.usgs.gov/

Text & Voice: Holly Strand

Utah, the Red State-Additional Reading:

Discover additional Wild About Utah pieces authored and voiced by Holly Strand, https://wildaboututah.org/author/holly-strand/

Chan,Marjorie A. and William T. Parry Rainbow of Rocks . Public Information Series 77. Utah Geological Survey. https://ugspub.nr.utah.gov/publications/public_information/pi-77.pdf [Accessed August 2025]

Geology Underfoot in Southern Utah by Richard L. Orndorff, Robert W. Wieder, and David G. Futey, Missoula, MT Mountain Press Publishing Company, 2006, https://mountain-press.com/products/geology-underfoot-in-southern-utah

Chronic, Halka. Roadside Geology of Utah. Missoula, MT Mountain Press Publishing Company, 1990 https://mountain-press.com/products/roadside-geology-utah

Fillmore, Robert, The Geology of the Parks, Monuments and Wildlands of Southern Utah, University of Utah Press, 2000, https://uofupress.com/books/geology-of-parks-monuments-and-wildlands-of-southern-utah/

December 16, 2010May 23, 2016

Colorado vs. Utah Snow

Utah snow in author's backyard: relatively light and dry--and definitely deep, Photo Copyright 2010 Holly Strand — Utah snow in author’s backyard:
relatively light and dry
–and definitely deep.
Copyright © 2010 Holly Strand

Hi I’m Holly Strand.

Growing up in Colorado, it never crossed my mind that the snow might be better somewhere else. I believed that my state was the center of the universe– at least as far as snow and skiing were concerned. A couple of decades passed and now I am a Utah resident. I couldn’t help but notice that snow quality here is well beyond satisfactory. And many Utah license plates claim the Greatest Snow on Earth. So, I wondered… Who has better snow? Colorado or Utah?

People usually assume that “great snow” means voluminous and powdery. So let’s compare the 2 states using measures of snow depth for volume and measures of water content for powder.

As far as snow depth, Alta takes the cake and wins mega points for Utah. According to data collected by ski area avalanche professionals, Alta’s average annual snowfall from Nov 1-Apr 30 is 530 inches. That’s 44 feet of snow ! A few other Utah resorts,–plus Colorado’s Wolf Creek Pass–come next with 400 + inches. After that, you get several 300+ inches resorts in both states. More in Colorado, but that’s just because there are more resorts in general. Colorado also has a bunch of areas with 200+ inches. But the point is that a handful of super-snowy resorts lead the pack and most of them are in Utah.

Next I located National Weather Service data for the average water content of freshly fallen snow. The lower the value, the drier the snow. It turns out that the mean water content of new snow decreases as you move eastward from the Pacific Coast to the Rockies. You get values around 12 % water content for the Sierras. This is the infamous Sierra Cement. Intermountain (including the Wasatch Mountains) values hover around 8.5%. The mean water content value for Central Rocky Mountain stations was close to 7%. So in general, Colorado has less watery snow. Of course there are localized anomalies in each state. But overall, Colorado appears to edge out Utah for light, dry, and fluffy snow.

So who has the best snow overall? Well, I guess I still haven’t solved that issue. Best to discuss it further after an exhilarating day on the slopes. Let us know what you think: Send us an email at wildaboututah@gmail.org

For data sources and archives of past Wild About Utah episodes visit www.wildaboututah.org

For Wild About Utah, I’m Holly Strand.

Credits:

Text: Holly Strand

Sources & Additional Reading:

Armstrong, R.L. and B.R. Armstrong. 1987. Snow and avalancheclimates of the western United States: a comparison of maritime, intermountain and continental conditions. IAHS Publ. 162
(Symposium at Davos 1986 – Avalanche Formation, Movement and Effects), 281–294

Baxter, M.A., C.E. Graves, and J.T. Moore, 2005: A Climatology of Snow to Liquid Ratio for the Contiguous United States, Weather and Forecasting, 20, 729-744.

Crocker, Tony. BESTSNOW.NET – an independent statistical analysis of snow characteristics (based on data collected by ski area avalanche professionals) at major North American ski resorts. https://webpages.charter.net/tcrocker818/ [accessed December 14, 2010]

Steenburgh, W. J., and T. I. Alcott, 2008. Secrets of the “Greatest Snow on Earth.” Bull. Amer. Meteor. Soc., 89, 1285-1293.