The City of Rocks

Granite spires the emigrants called the Silent City

City of Rocks is an encirclement of granite spires rising out of the sagebrush of south-central Idaho, two miles north of the Utah line, and emigrants on their way to California called it the Silent City of Rocks. The stone was intruded into the crust at two widely separated times. Most of the spires belong to the Almo pluton, about 28 million years old, but some are cut from the Green Creek Complex, 2.5 billion years old and among the oldest rock in the western United States. As the granite cooled and the ground above it wore away it cracked along joints, and thin plates and scales flaked off them, a process called exfoliation that carved the rock into its assortment of shapes.

People were here long before the wagons. The country around it has been home to the Shoshone, Paiute and their ancestors for thousands of years, since hunters followed game into the Great Basin at the end of the Ice Age; Fremont-style grayware pottery shows contact with the farmers to the south. The Shoshone and Bannock hunted the buffalo that once roamed here and gathered pine nuts each fall from the pinyon woods, a harvest members of the Fort Hall Reservation still make. Peter Skene Ogden's beaver trappers noted the rocks in 1826, then moved on for lack of beaver.

From 1843 the wagons came. The California Trail climbed the Raft River valley, passed through the City of Rocks and crossed Granite Pass toward the Humboldt River, and the rocks marked roughly the halfway point to California. Travellers rested or nooned at Circle Creek, and one emigrant in 1849 saw the distant spires one August like water thrown into the air from hydrants. In 1852 some 52,000 people passed through on their way to the gold rush. Many wrote their names in axle grease on the granite, at Register Rock and Camp Rock, and those signatures, along with wagon ruts worn into the stone, can still be seen. In the south of the reserve the Salt Lake Alternate Trail, first recorded by Mormon Battalion soldiers in 1847, joined the main trail, and after the railroad came it carried the stage line from Kelton, Utah, to Boise.

Homesteaders tried dryland farms between 1910 and 1919 and mostly gave up by the 1920s, and ranching took over. Climbers from Utah found the spires. The City now has more than 1,000 traditional and bolted routes, and in the 1980s it held some of the hardest in the country, many put up by the Idaho climber Tony Yaniro. Congress made it a National Reserve in 1988, run jointly with Idaho Parks and Recreation, and it draws over 80,000 visitors a year.