. Use your observations to make predictions. The Merced River flows from Yosemite Valley at an elevation of ∼1,200 meters above sea level in central Yosemite Valley to an elevation of ∼250 m where the river enters Lake McClure: a reservoir in the San Joaquin Valley west of Yosemite Valley. The actual distance the river travels along its channel from Yosemite to the upper end of Lake McClure is more than 65 km. You can examine the Merced River course between latitude 37.72°N, longitude 119.63°W (central Yosemite Valley) and 37.602°N, 120.100°W (inlet to Lake McClure on the Merced River) using Google Earth.