Glacier Lake (Union)
Reachcode: 17060105000776 | Area: 53.0 acres | Shoreline: 1.6 mi | View on Interactive Map
(From Atlas of Oregon Lakes, Johnson et al. 1985) Glacier Lake, as the name implies, is a spectacularly beautiful glacial lake located high in the Eagle Cap Wilderness of northeastern Oregon. It is a classic example of a cirque lake, its basin scoured out of the mountain side by a glacier during the Pleistocene Epoch. The mode of origin is obvious in the steep—walled, amphitheater shaped basin and in the deep bowl of the lake. A maximum depth of over 120 feet is attained at the western end, with a second depression near the southern shore of the eastern end. Most of the shallow area is in the northeast part of the lake where there are several islands. The West Fork of the Wallowa River originates in Glacier Lake. Inflow is from the melting of heavy snows that accumulate in the small, rugged drainage basin. Fishing for brook trout in the lake can be excellent in late summer, but most visitors come simply to enjoy the awesome glacial landscape.
The water in the deeper part of the lake (depths greater than 30 feet) is perennially cold, close to 39 degrees Fahrenheit (4 degrees Celsius) which is the temperature of maximum density. During late summer, the surface warms somewhat, although the surface temperature seldom exceeds 50 degrees Fahrenheit (10 degrees Celsius). The considerable depth of the lake (mean depth = 52 feet) and the high altitude (8200 feet) are responsible for the cool temperatures. Water in the lake is very low in chemical constituents. Conductivity, alkalinity, and major ion concentrations are among the lowest of any lakes in Oregon. The most abundant ion, Ca++, may result from the weathering of glacial flour in the drainage basin. Water transparency is excellent and the population of plankton and concentration of chlorophyll are low. Oxygen is saturated at all depths.