Of the small residual glaciers mentioned in the preceding chapter, I have found sixty-five in that portion of the range lying between latitude 36 deg. 30' and 39 deg. They occur singly or in small groups on the north sides of the peaks of the High Sierra, sheltered beneath broad frosty shadows, in amphitheaters of their own making, where the snow, shooting down from the surrounding heights in avalanches, is most abundant. Over two thirds of the entire number lie between latitude 37 deg. and 38 deg., and form the highest fountains of the San Joaquin, Merced, Tuolumne, and Owen's rivers.