Merced Peak, an 11,731-foot summit in the Clark Range near Yosemite’s southern border, is the highest point in the range and rises above nearby Red Peak, Gray Peak, and Mount Clark. It holds an important place in Yosemite science because in 1871 John Muir discovered an active alpine glacier below the peak, evidence that helped gain acceptance for his view that Yosemite Valley was shaped by glacial action. The mountain also lies in an alpine climate zone where Pacific weather is lifted over the Sierra Nevada, bringing rain and snow that create severe high-mountain conditions.