The "South Window" arch at Arches National Park, near Moab, Utah, on June 30, 2009.
CNET News reporter Daniel Terdiman spent two days in eastern Utah on Road Trip 2009, and visited Arches, Canyonlands National Park, Monument Valley Navajo Tribal Park and the outstanding scenic route of Utah highway 128 that leads to Moab.
Formations like the Southern Window, as well as others in Arches National Park happen for a number of different reasons. "Cracks in fins and the contact layer between different layers of rock are good places for arches to begin," an information display at the Arches visitor center explains. "Both mechanical and chemical forces attack these weaker spots and begin the processes which form arches."
According to the National Park Service, "Balanced Rock clearly shows the various layers responsible for this amazing defiance of gravity. The caprock of the hard Slick Rock Member of the Entrada Sandstone is perched upon a pedestal of mudstone. This softer Dewey Bridge Member of the Carmel Formation weathers more quickly than the resistant rock above. Eventually, the faster-eroding Dewey Bridge will cause the collapse of Balanced Rock."
On September 1, 1991, a huge section of the 306-foot-long arch collapsed, leaving 180 tons of rock crumbled on the ground below.
"What caused this cataclysmic event? Water had been slowly shaping the arch for countless centuries, dissolving cement between sand grains, seeping into tiny cracks, freezing and expanding. What had finally upset the delicate balance," reads an information display at Arches. "Unseasonably heavy rains the preceding ten days may have filled pore spaces within the sandstone. The added weight may have finally overwhelmed the rock slab in its timeless struggle with gravity."
The beautiful and jaw-dropping Newspaper Rock National Historical Site, on the southern road into Canyonlands National Park in eastern Utah.
"Newspaper Rock is a petroglyph panel etched in sandstone that records approximately 2,000 years of early man's activities," a display sign reads. "Prehistoric peoples, probably from the Archaic, Basketmaker, Fremont and Pueblo cultures, etched on the rock from B.C. time to A.D. 1300. In historic times, Utah and Navajo tribesmen, as well as Anglos, left their contributions.
"There are no known methods of dating rock art. In interpreting the figures on the rock, scholars are undecided as to their meaning or have yet to decipher them. In Navajo, the rock is called Tse' Hane' (rock that tells a story)."
A major section of Canyonlands National Park, in eastern Utah, the Needles are "rock pinnacles banded in red and white. Earth movements fractured the rock and water and freezing and thawing eroded it into the jumbled terrain of today," according to the National Park Service.
Utah Highway 128 between Interstate 70 and US 191 follows the path of the Colorado River, which along its multistate journey has carved out things like the Grand Canyon. Here, it has helped create canyons, though perhaps not of the scope and scale of the Grand Canyon.