| Rock Lake | |
| Coords: | 47.1778°N -117.6836°W |
| Basin Countries: | United States |
| Length: | 7miles[1] |
| Width: | 1miles |
| Area: | 2190acres |
| Max-Depth: | 375feet |
| Elevation: | 1728feet |
| Cities: | St. John |
| Pushpin Map: | Washington#USA |
| Pushpin Map Alt: | Location of Rock Lake in Washington, USA. |
Rock Lake is the deepest and largest of all scabland lakes left behind from the Missoula Floods, and holds that distinction for all of eastern Washington.[2] [3] At its deepest, it is more than 360feet deep, although the official measurement is uncertain.[4] [5] The lake is over 7miles long and averages 1miles in width, and is accessible via a solitary landing area located on the south end. The rest of the shoreline is inaccessible to vehicles, other than a few private properties.
Located approximately 30miles south of Cheney, Rock Lake is in a moderately remote location. Other towns in the area include Sprague, St. John, and Rosalia, although all are a number of miles away.
Rock Lake receives the majority of its water from Rock Creek, which further downstream is a tributary of the Palouse River, as well as Negro Creek. The lake is approximately long and 1miles wide, having a wildly varying depth with steep dropoffs plunging over 300 feet down.[6] About half a mile from the boat launch, the lake's characteristic geography can be seen: high basalt cliff walls on either side with rock pillars and spires protruding from the bottom. The steep basalt cliffs and stone pinnacles which can rupture a hull and a lack of shoreline, coupled with the wind tunnel effect from the region's notable Palouse winds, have led to many deaths on the lake.[6] [7] In addition to the perils in the lake, its banks are also habitat for rattlesnakes in the spring and summer months.[7]
The primary recreation activity on Rock Lake is fishing. Popular sport fishing species in the lake include: Crappie, Brown trout, Bluegill, and Rainbow trout.
Running along the eastern shore of the lake is the John Wayne Pioneer Trail, which is a converted rail trail.[7] This section of trail is now open, completing open access from Idaho to North Bend, Wa with the addition of the rail bridge over the Columbia River near Vantage..[8] [9]
A dam was first considered at the mouth of Rock Lake in the lake 1930s, and base columns were installed.[10] The idea of a dam was abandoned at that point, because of the difficulty the topography would present.
Recently, interest in building a dam at this site has been renewed. Representatives of the Palouse-Rock Lake Conservation District are interested in having a dam built for the primary purpose of stabilizing water supply to right-holders below the dam by creating a consistent flow throughout the year. The current plans for a dam would impound 110,000-120,000 acre feet of water.[11]