SWEETWATER COUNTY — Continuing our tour of the Great Divide and Green Rivers Basins, today we take a look at the Oregon Trail and the White Mountain Petroglyphs. These historic, cultural gems are accessible by car, though a four wheel drive with good clearance is recommended. If you go, take all the pictures you want, but please leave the area as you found it for the enjoyment of others.
Oregon Trail
By Julie Francis
Upon cresting the Continental Divide at South Pass, westbound emigrants on the Oregon, California and Mormon Pioneer trails faced an arduous journey across the Green River Basin. The high desert landscape, as well as the mountain ranges and hogbacks of the overthrust belt, presented a variety of challenges to travelers during the mid-1800s. Geological landforms often played an important role in determining specific routes.
From South Pass, the primary route headed southwest toward what is now the town of Granger and onwards to Fort Bridger. This route provided much needed fresh water, grass for livestock, and the opportunity to rest and replenish supplies at Fort Bridger. From Fort Bridger, Mormons continued southwest across the Wasatch Range and faced perilous descents of the steep canyons on the western slope to the Salt Lake Valley. Most Oregon and California-bound travelers took a sharp turn north at Fort Bridger to Muddy Creek. Cumberland Gap, cut by Muddy Creek through the Hogback, served as access to the overthrust belt and the Bear River Divide. Emigrants followed several variants established along different creeks to reach the divide, often traveling at elevations significantly higher than South Pass. The routes converged at a low pass and descended Bridger Creek to the Bear River and then onto the Snake River plain in Idaho.
The Fort Bridger route to Oregon and California was far from direct, leading to the opening of several significant cutoffs. These generally followed a more westerly course across the Green River Basin and joined the main trail north of present-day Kemmerer. These cutoffs shortened travel time by as much as three days, but emigrants had to cross vast waterless stretches between South Pass and the Green River and were unable to go to Fort Bridger to resupply. The Sublette Cutoff, established in the 1840s, left the main route at “Parting of the Ways” near South Pass and headed west over the high, dry benches of the Green River Basin. After crossing the Green River south of present-day LaBarge, emigrants inscribed and painted their names on the soft Wasatch Formation sandstones at Names Hill, alongside Native American images. The Slate Creek cutoff took a more southerly route, and the Lander Cutoff headed west across the upper Green River Basin, crossing the river north of present day Big Piney. This road was built by the U.S. Army in 1857 as part of a network of wagon roads across the West.
Travelers on all routes had to cross the Green River to continue their journey. At low water, the river could be forded. During high water, ferries operated at key crossings. Ferry owners charged high fees, and the crossings were dangerous, often resulting in loss of wagons, livestock, belongings and lives. Eventually, the ferries were replaced by bridges on what became the modern state highway system. Even today, there are only three highway crossings of the Green River, all in the general vicinity of the historic ferry crossings.
Green River Basin Rock Art – White Mountain Petroglyphs
By Julie Francis
The vestiges of Eocene Lake Gosiute exposed on the modern land surface often consist of soft sandstones and mudstones. Easily sculpted by both water and wind, slightly harder beds of rock have sometimes been exposed by downcutting of the Green River and other streams or along the sides of buttes capped by harder rocks more resistant to erosion. The rocks of these bluffs and walls are often quite massive, with few bedding planes, fractures or seams, and they made for an ideal canvas on which native peoples and emigrants engraved, chiseled, abraded and painted a variety of images. Unfortunately, because the rocks are so soft, the glyphs do not stand up well to the ravages of time, and most of the Native American rock art of the Green River basin is likely less than 1,000 years old.
Hints that native people of the Green River Basin made rock art for thousands of years have been found on the flanks of Steamboat Mountain. There, a small overhang contains the images of humans and mountain sheep, made by a method called pecking, and almost completely coated by layers of patina (or rock varnish). Both the varnish and petroglyphs have survived because the overhang is protected from the wind, which has “sandblasted” nearby rock surfaces. AMS radiocarbon dating of minute pieces of organic material embedded in the varnish suggest that these images could have been made as long as 11,000 years ago. The radiocarbon age certainly does not provide an exact date of manufacture but clearly indicates a substantial antiquity of these images.
The incised glyphs of the White Mountain Petroglyph site stand in stark contrast to these older images. Hundreds of renderings of bison, bear, elk and other animals, along with some human figures, animal tracks, plants and geometric designs have been incised into the soft sandstone north of Rock Springs. Many of the animals pictured at this site are considered to be spiritually powerful creatures, whose power and wisdom was sought by humans, and these images indicate ceremonial and spiritual use, probably beginning in the Late Prehistoric Period about 1,000 to 1,500 years ago. Human hand and finger grooves, made simply by repeated gouging of the rock over the millennia, provide testament to the power of the place as well as to the fragility of the soft rock. In addition to these images, White Mountain contains many historic period images – horse-mounted warriors, some holding bows, others holding rifles and clubs, protected by shields and often engaged in battle. This imagery, commonly termed Biographic style art, reflects the major disruption, conflict and changes experienced by native peoples – many of whom were ancestors of the modern Shoshone and Ute – after the entry of Euro-American emigrants into the region.
