Hillman Peak—Highest Point on Rim of Crater Lake
Origin of the Lake.
The water of Crater Lake comes from rain and snow. The average annual precipitation is 69 inches. The lake has no inlet and no outlet, except seepage. Evaporation, seepage, and precipitation are in a state of relative balance which maintains an approximately constant water level. In 1957, the lake level was the highest recorded since 1908. There is an annual variation of from 1 to 3 feet, the level being highest in spring and lowest in autumn.
Color of the Lake.
The deep blue of the lake is believed to be caused chiefly by the scattering of sunlight in water of exceptional depth and clearness, the blue rays of sunlight being bent back upward, rays of other colors being absorbed.
Wildlife
Mammals.
There are about 60 kinds, of which the golden-mantled ground squirrels are among the most conspicuous. They resemble large chipmunks but have stockier bodies, shorter tails and no stripes on their heads. On each side there is a broad, white stripe sandwiched between two dark stripes. Two species of true chipmunks with striped heads also are numerous. The small, tree-inhabiting chickaree, dark brown above and whitish below, is common; and the porcupine is frequently seen. It is advisable to enjoy these and all other small mammals without actual contact because occasionally they carry diseases which can become serious if transmitted to humans.
The large fat-bodied marmot (a mountain woodchuck) lives in high rocky places and on roadsides. The plaintive bleating “yenk, yenk” of the tiny “rock rabbit” (cony) issues from crevices in the talus. Snowshoe hares, brown in summer and white in winter, are sparingly present around forest clearings, such as at the south and east entrances.
Martens are rather common; they are slim brown animals somewhat like large minks but they can climb trees like squirrels. Less often seen are weasels, badgers, minks, red foxes, and coyotes. The gray fox, bobcat, and mountain lion (cougar) are rare.