- Deschutes County)
(From Atlas of Oregon Lakes, Johnson et al. 1985). Elk Lake is a beautiful mountain lake located in the volcanic landscape of the upper Deschutes River Basin. It lies southeast of the Three Sisters Range at an elevation of 4884 feet above sea level, and is accessible from the Cascade Lakes Highway. The lake received its name because of the large number of elk that used to be seen nearby in the summer. Elk Lake, like many other high Cascade Lakes was formed as a result of volcanic activity, when a lava flow impounded the flow of several small streams. Surface flow to the lake is intermittent and occurs during the snowmelt season; subsurface seepage through the permeable volcanic bedrock accounts for most of the water in the lake. There is no surface outlet. It is not a particularly deep lake; average depth is less than 18 feet, and the maximum depth is about 62 feet. The shoreline generally falls off gradually and is rocky. Bottom material is rock and sand.
Elk Lake has long been one of the most popular lakes in this lovely recreation area on the east slope of the Cascades. The Three Sisters form a spectacular backdrop to the north and symmetrical Bachelor Butte looms over the lake to the east. The lake is used heavily for recreation, with sailing and swimming activities heading the list. Fishermen also frequent the lake, as much for its scenic beauty as for the angling success. For many years Elk Lake was famous for its fishing, and was also long known as a source for fish eggs. For example, in January 1919 some 350,000 eastern brook trout eggs were gathered there, brought to Bend by sled, then dispatched by auto to the Bonneville Hatchery (Hatton 1980). In recent years there has also been good fishing; eastern brook trout make up a large share of the catch, with some rainbow trout and stocked kokanee or land—locked salmon. A 10 mile per hour speed limit for motorboats is in effect on the lake. Extensive recreational facilities have been provided at or near the lake by the Deschutes National Forest. There are four campgrounds, three boat launch sites, and picnic grounds located around the lake. An excellent private resort with cabins is located on the west side, and there are about three dozen summer homes around the perimeter of the lake. Most of these are on the west shore with a few on the east. Swimming beaches exist at the resort and at each of the campgrounds. Trails to high lake areas such as the Horse Lake and Mink Lake basins start here, so it is a good base area for hikers. The lake freezes over most winters, and opens in late April; however, in most years the roads are blocked by snow until late May.
Elk Lake is elongate in shape with the major axis of the basin oriented north and south. The deepest part of the lake is located at the southern end. Most of it is shallower than 20 feet deep, and as a consequence it becomes relatively warm during the summer. Water temperature during the summer commonly exceeds 68 degrees F. (20 degrees C.), and there is usually very little temperature stratification in the lake. Although 68 degrees Fahrenheit is cool for swimming, it is warmer than most of the deeper lakes in this recreation area, and Elk Lake is a popular swimming lake.
The lake was surveyed for nutrient enrichment and bacterial contamination in 1969 by the Department of Environmental Quality. The results of the survey indicated generally good water quality conditions, although there was some evidence of enrichment and bacteria derived from inadequately designed or maintained sewage facilities. The shallow average depth of the lake makes it vulnerable to nutrient enrichment.
Although the indices of trophic state clearly establish Elk Lake as being oligotrophic, there are some indications that cultural activities may be increasing the trophic status. At times, higher than normal phosphorus concentrations are observed, and stimulated phytoplankton growth increases the pH of the surface water. Also, the phytoplankton species present indicate a trophic state higher than oligotrophic. Fragilaria crotonensis was common in samples collected in 1981 and 1982; this diatom is usually observed in mesotrophic to eutrophic lakes and rarely in oligotrophic lakes. Asterionella formosa also occurs most commonly in mesotrophic lakes, but is not uncommon in either oligotrophic or eutrophic lakes.