 Of the many Native American tribes that have lived on the Merced River the most prominent were the Miwok ( consisting of Plains Miwok and Sierra Miwok ) , Paiute , and Ahwahnechee . Many Plains Miwok settled in the lowlands along the lower Merced River . The Sierra ( or Mountain ) Miwok lived in the upper Merced Canyon and in Yosemite Valley , and at the time the first white explorers came to the area , there were about 450 Sierra Miwok split among ten permanent villages . Paiute , of origin from the eastern Sierra near the Mono Lake area , also lived in the upper watershed of the Merced River . The Sierra Miwok and Mono Lake Paiute eventually , through cultural interaction over time , formed a new culture , the Ahwahnechee , derived from Ahwahnee , meaning " the valley shaped like a big mouth " ( referring to U @-@ shaped Yosemite Valley ) . 
