

Photographer: Ray Boren
Summary Author: Ray Boren
Almost two centuries ago, on July 4, 1830, a brigade of about 80 fur trappers and traders led by William Sublette, headed toward the Wind River region just to the west, paused to celebrate the Fourth of July — Independence Day in the young United States of America. They camped beside a massive, free-standing mound of bald granite along central Wyoming’s Sweetwater River. Sublette is generally credited with giving the monolith its name: Independence Rock, shown here in a photograph taken on June 19, 2025.
During the mid-19th century, this emigrant route over the Continental Divide and through North America’s Rocky Mountains was traveled by an estimated half-million explorers, adventurers, would-be gold miners, farmers, tradesmen and other settlers — men, women and children. All were walking, riding horses or seated on often oxen-powered wagons, and some were even pulling handcarts. The Oregon, Mormon Pioneer and California National Historic Trails and the route of the Pony Express all passed by this impressive outcrop. Independence Rock and the Fourth of July became goals for pioneers because the landmark was about halfway between their trek’s beginnings, near the Missouri River, and their Far West and Pacific Coast destinations, which they hoped to reach before snow started to fall in the Sierra Nevadas and other ranges later in the year.
In diaries and letters, emigrants variously wrote that the great mound looked like “a huge whale,” “a giant bowl turned upside down,” or “a big elephant mired up to its sides in the mud.” And on cliffs, in alcoves and caves, and on the rock’s rounded top, thousands of them scratched, chiseled or wrote with paint, axle grease, or tar their names, initials and dates onto the granite. Time, weather, erosion and rock-covering lichen have erased or obscured most of the inscriptions, but scores remain, as shown in the bottom photo (also taken on June 19). One of the earliest known signatures, made by “M.K. Hugh” in 1824, has vanished. But others, even from the 1840s and 1850s, can be found by determined searchers, especially along a path that encircles the rock.
The emigrants, as an informational sign at Independence Rock observes, probably did not realize they were beneficiaries of millions of years of geologic activity. The monolith — roughly 1,900 feet (580 meters) long, 850 feet (260 m) wide, and 130 feet (40 m) high — and other, more-jagged peaks nearby are composed of Archean granite, a hard, coarse-grained igneous rock that slowly cooled under the Earth’s surface. The rise and fall of the land and erosion eventually exposed the summits we see today. A highway rest stop along Wyoming 220 now provides viewpoints and pathways to the steep-sided mount, which was designated a National Historic Landmark in 1961, and which is managed today by the State of Wyoming as the Independence Rock State Historic Site.
Independence Rock, Wyoming Coordinates: 42.4935, -107.1318
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