Hydrology of Crater, East and Davis Lakes, Oregon by Kenneth N. Phillips
RECORDS OF LAKE LEVEL
Records of the lake level are fragmentary (table 12). All water levels herein are referred to U.S. Geological Survey bench mark P-9 (alt. 4,395.25 ft, datum of 1929, supp. adjustment of 1947), set in a boulder at the northwest edge of the lake.
The lake level varies in response to runoff conditions of the current water year and to a lesser extent to those of 1 or 2 immediately preceding years. The seasonal peak occurs in May or June, soon after the seasonal peak flow in Odell Creek at the station near Crescent. By early autumn the lake level is usually 2 or 3 feet below its seasonal peak. The changes of level within a single season are considerably greater than those of Crater and East Lakes.
Peak stages are of particular interest because of their implications with respect to climate and runoff over the past several centuries. The highest stage observed in recent years was 4,393.2 feet (from a floodmark) in June 1957. A floodmark at the same level was noted in 1934 during a survey of a proposed lake-outlet channel (C. C. Fisher, U.S. Bur. Reclamation, unpub. data, 1936), and it may represent a stage reached in 1904. The highest level the lake probably ever attained, 4,395.4 feet, is marked by (1) the lower limit of living crustose lichens on the lava rocks along the northern shore, and (2) the formation of a small level terrace or bar at the northeastern shore near the lava dam. A western yellow pine tree that grew on that terrace was cut in 1958, and the stump was found later to have 235 annual growth rings (Lawrence, 1961, p. 344). Older and very large yellow pine trees are living at levels less than 1 foot higher. A reasonable inference is that the high level of 4,395.4 feet was reached sometime prior to the year 1723 and has probably never been materially exceeded.