This isolated mass of granite sprawls over 27 acres next to the meandering Sweetwater River. More than a mile in circumference, Independence Rock is 700 feet wide and 1,900 feet long. Its highest point, 136 feet above the rolling prairie, stands as tall as a twelve-story building. The granite outcrops in the Sweetwater River Valley are buried peaks of the Granite Mountains, which collapsed along faults around three to five million years ago. Wind and weather have exposed the ancient peaks seen throughout the area, including Independence Rock. Many well-known trail landmarks are located in this area, including a gorge called Devil's Gate. Millions of years ago, the Sweetwater River established its path through the valley when it was filled with sediments. The river maintained its route in the entrenched channel, cutting through the granite to form the gorge. Split Rock, located 20 miles west of Independence Rock, is another famous landmark used by Native Americans, trappers, and emigrants traveling through the Sweetwater Valley. The V-shaped cleft or split near the top of the Granite Mountains is visible from more than a day's journey away.