- Deschutes County)
(From Atlas of Oregon Lakes, Johnson et al. 1985) Lava Lake is one of many scenic mountain lakes on the east slope of the Central Oregon Cascades accessible from the Cascade Lakes Highway. It takes its name from the surrounding lava flows, which are prominent along the east shoreline. Lava flows from Bachelor Butte probably altered drainage patterns in the area and formed the lake with a lava dam. Very little surface drainage has developed in this volcanic terrain, and there are no permanent surface streams entering the lake. Wire Meadow, a marshland of about 35 acres with many seeps and small springs, is the source of most of the surface water draining into Lava Lake. Ordinarily there is no surface outlet, but during periods of high water there is some flow south through an open channel into Little Lava Lake, from which the Deschutes River flows. Thus, Lava Lake may be considered as the source of the Deschutes River. However, this claim must be considered tenuous in a region of permeable volcanic materials where groundwater flow is prevalent. Water level tends to fluctuate an average of three to four feet per year with high water occurring in late summer.
Lava Lake is relatively old, as evidenced by the extensive vegetation along the shallow littoral areas. A variety of macrophytes grow on the southwest and northwest ends of the lake and the adjacent meadows are possibly remnants of what was once a larger lake area. Another indication of aging is the layer of muck on the lake bottom, which is reported by skin divers to be four to five feet deep in some places. Several subsurface springs enter the lake in the northeast corner. In a 1962 survey by the Oregon Department of Fish and Wildlife, springs at 20 feet below the water surface of Lava Lake registered 60 degrees Fahrenheit (16 degrees Celsius); deeper springs were 45 degrees Fahrenheit (7 degrees Celsius). Concentrations of large trout were observed more frequently in the spring areas, moreso than in other locations in the lake.
There is a good Forest Service campground at Lava Lake; there is also a private resort on the south shore. Angling for brook trout and rainbow trout is excellent. Brook trout outnumber the rainbow trout, which have been stocked only in recent years; but the rainbow trout are generally larger. Fly fishing is particularly good because of the extensive shoal areas.
The Lava Lake basin has a somewhat rectangular shape, with the long axis oriented north-south. The sides of the basin are relatively steep, especially along the north and east of the lake where the lava dam that formed the lake is located. The mineral content of the water in Lava Lake is typical of Cascade lakes for the most part, although sulfate appears to be somewhat above average. The concentration of chlorophyl is low, and water transparency is average. The concentration of phosphorus observed on 8/21/81 is surprisingly high (0.53 ppm). The concentration of phosphorus in Little Lava Lake was also high, suggesting that the springs feeding these lakes may be rich in natural phosphorus. At present, Lava lake is oligotrophic, with some tendency to mesotrophic as indicated by the chlorophyl and phosphorus content.