POTD July 15, 2013: Navajo Indian Reservation, San Juan County, Utah

Navajo Indian Reservation, San Juan County, Utah
Photographer: Phil Powlick

The wind has formed ripples on the surface of a dune in Monument Valley along the Utah-Arizona border.

POTD July 12, 2013: Kolob Canyons, Zion National Park, Washington County, Utah

Kolob Canyons, Zion National Park, Washington County, Utah
Photographer: Michael Vanden Berg

Jurassic-age Navajo Sandstone forms the massive red cliffs of the often-overlooked Kolob Canyons area of Zion National Park. Hanging valleys are present where relatively small tributary streams have eroded downward at a slower rate than the larger trunk stream.

POTD July 11, 2013: Rose Canyon, Salt Lake County, Utah.

Rose Canyon, Salt Lake County, Utah.
Photographer: Michael Vanden Berg

Step Mountain is aptly named for several resistant Tertiary-age andesite dikes that display exceptional horizontal columnar joints.

POTD July 10, 2013: Wasatch Range, Utah & Wasatch Counties, Utah.

Wasatch Range, Utah & Wasatch Counties, Utah
Photographer: Robert F. Biek

Framed by blooming gray rabbitbrush (Chrysothamnus nauseosus) above the east shore of Deer Creek Reservoir, Mt. Timpanogos is formed of Pennsylvanian-age, shallow- marine limestone and sandstone of the Oquirrh Formation. The small patch of snow is in Cascade Cirque, one of several glacier-carved basins on the east side of the 11,749-foot-tall mountain.

POTD July 9, 2013: East of the Green River, Grand County, Utah.

East of the Green River, Grand County, Utah.

Photographer: Don DeBlieux

A summer evening arrives with the promise of cooler temperatures at the UGS paleontology camp near the Crystal Geyser Dinosaur Quarry.

POTD July 8, 2013: Capitol Reef National Park, Garfield County, Utah

Capitol Reef National Park, Garfield County, Utah
Photographer: Paul Kuehne

The Waterpocket Fold affords a wonderful view of the geology of Grand Gulch. The Entrada Sandstone (reddish-orange rock on the right) and Navajo Sandstone (pale-orange rock on the left and middle distance) were formed in a desert  environment beginning about 185 million years ago in the Jurassic Period.

POTD July 5, 2013: Cookie Jar Butte, Glen Canyon National Recreation Area, Kane County, Utah

Cookie Jar Butte,Glen Canyon National Recreation Area, Kane County.
Photographer: Jim Davis

Cookie Jar Butte, named for the gigantic, cylindrical weathering pits that dot its peninsula, towers above Padre Bay on Lake Powell.

POTD July 4, 2013: Dollar Lake, High Uintas Wilderness, Duchesne County, Utah

Dollar Lake, High Uintas Wilderness, Duchesne County, Utah
Photographer: Mike Hylland

To the south of Dollar Lake in the Uinta Mountains, cliffs of Precambrian-age sedimentary strata rise abruptly at the head of the Henrys Fork basin. The leftmost peak lit by the morning sun is Utah’s highest mountain, Kings Peak (13,528 feet), which was named for Clarence King, first director of the U.S. Geological Survey.

POTD July 3, 2013: Devils Postpile, Dugway Proving Ground, Tooele County, Utah

Dugway Proving Ground, Tooele County, Utah.
Photographer: Don Clark

Locally known as Devils Postpile, this andesite intrusion in the southern Cedar Mountains displays well developed columnar cooling joints.

POTD July 2, 2013: White Pine rock slide, Little Cottonwood Canyon, Salt Lake County, Utah

 Southeast of Salt Lake City, Salt Lake County, Utah
Photographer: Michael Vanden Berg

The White Pine rock slide covers the floor of Little Cottonwood Canyon with boulders of granitic rock of the Tertiary-age Little Cottonwood stock. These rocks broke loose from the north side of the glacially-carved canyon several thousand years ago.