Merced River, CA

The Merced River, in the central part of the U.S. state of California, is approximately 112 miles (180 km) long, flowing from the Sierra Nevada into the Central Valley and the San Joaquin River, which ultimately flows to the Pacific Ocean. It is most well known for its swift and steep course through the southern part of Yosemite National Park, having carved out the world-famous Yosemite Valley. The river's character changes dramatically once it reaches the foothills and the lowlands; it becomes a slow-moving waterway streaming through farmland.

Beginning at the confluence of the Lyell Fork, Triple Peak Fork and Merced Peak Fork in the southeastern corner of Yosemite National Park, near Merced Lake, the Merced River flows 112 miles (180 km) westward through a series of canyons, gorges and finally the flat plains of the Central Valley. Its headwaters at 7,917 feet (2,413 m) lie at the foot of the Clark Range, a subrange of the Sierra Nevada. The river flows through a steep-walled granite canyon for nearly 10 miles (16 km) before spilling into Little Yosemite Valley, a glacial valley that precedes the more famous Yosemite Valley. After meeting up with the John Muir Trail, the Merced River drops over Nevada Falls and Vernal Falls, receives Illilouette Creek, and passes into the main Yosemite Valley, where it meanders between pine forests that fill the valley floor.

Tenaya, Yosemite, Bridalveil and Pigeon Creeks join the Merced before it breaches the glacial moraine at the valley's end. From there the river picks up Cascade Creek and turns south near El Portal, flowing through Merced River Canyon. State Route 140 follows the river out of the west entrance to the national park, a few miles before the South Fork Merced River, the largest tributary, joins from the left. The river arcs northwest to receive the North Fork, and a few miles after it enters Lake McClure, formed by New Exchequer Dam. The remainder of the river continues to flow west across the Central Valley before joining the San Joaquin River a few miles south of Turlock.