Merced River

From its source on the south side of Mount Lyell at 13,114 feet, through a glacially carved canyon within Yosemite National Park, the river flows downstream to Lake McClure Reservoir. The South Fork possesses one of the few remaining pristine Sierra Nevada fisheries with self-sustaining populations of rainbow, eastern brook, and brown trout. Archeology and wildlife are also noteworthy. This river is majorily responsible for creating the Yosemite valley as we know it. The river first formed about 10 million years ago as the Seirra Nevadas rose due to seismic waves. The Merced River steepened and cut the canyon deeper creating Yosemite Valley as we know it.