Fish Lake (197) (Jackson)

Reachcode: 17100307001170 | Area: 383.5 acres | Shoreline: 6.2 mi | View on Interactive Map

(From Atlas of Oregon Lakes, Johnson et al. 1985)  Fish Lake is a large reservoir located at the foot of beautiful Mt. McLoughlin in the southern Oregon Cascades. It was formed from a small natural lake, which was considerably enlarged in 1915 by the construction of a rock-faced, earthfill dam on the North Fork of Little Butte Creek. Built by the Bureau of Reclamation, it is now a part of the Medford Irrigation District. There is no significant natural surface flow into the lake, this being a region of highly permeable volcanic materials where groundwater movement dominates. Since 1923 water has been diverted from Fourmile Lake in the Klamath River Basin through the Cascade Canal, and discharged into the lava terrain about one and one-half miles above Fish Lake. There it seeps in and reappears as springs at the head of the lake. The outflow into the North Fork of Little Butte Creek is used for irrigation near Eagle Point and Medford.

Fish Lake was designed as a multi-purpose facility and it has become well known as a recreation area. Swimming, boating, camping and fishing draw large numbers of visitors. The shoreline is entirely in federal ownership and the Forest Service maintains two campgrounds, picnic areas and boat launching facilities. On the east end of the lake is a private resort with cabins, a store and trailer spaces. There are also about 30 summer homes around the shore on land leased from the Forest Service.

The lake is relatively shallow, with a mean depth of 18 feet and a maximum depth of only 31 feet at full pool. The shape is elongate, but less branched than is usual for a reservoir. The concentrations of major ions are lower than average for lakes in the Rogue River Basin; conductivity and alkalinity are among the lowest. In spite of the shallow depths, no significant growth of submerged macrophytes has developed. The concentration of phosphorus is somewhat above average and algal blooms occur regularly. Water transparency varies considerably throughout the year and at times is greater than in most other lakes of the Rogue River Basin. The relatively high elevation may help to diminish any tendency for advancing trophic conditions in Fish Lake and it is classified as mesotrophic.