Eagle Lake (Lassen County)

Eagle Lake is home to osprey (Pandion haliaetus) and bald eagles (Haliaeetus leucocephalus), from which it gets its name. Eagle Lake is the only watershed which supports native Eagle Lake trout (Oncorhynchus mykiss aquilarum). This subspecies of rainbow trout can grow to very large sizes, possibly having evolved to live longer as low flows often restrict spawning runs up their main spawning stream, Pine Creek. The average size of Eagle Lake trout are about and can exceed . Adults quickly grow to a size of in three years and can live for up to 11 years. Since these Modoc Lakes are high in alkalinity, the trout have evolved to be the only known trout subspecies capable of surviving in the alkaline waters of Eagle Lake. Eagle Lake Rainbow descendants, however, are planted with high success in many other lakes in California. These trout were once so abundant that there was a commercial fishery for them in the late 19th century. At the same time, extensive logging and heavy livestock grazing caused Pine Creek to change from a permanent to an intermittent stream in its lower reaches. In the early 1950s the few remaining eagle lake rainbow trout at the mouth of Pine Creek were rescued and used to start a hatchery program to maintain the species and the sport fishery. ==Watershed and tributaries==

Eagle Lake was once part of a large lake on the Modoc Plateau millions of years ago. The modern lake is long by wide and is highly alkaline (pH 8-9). The lake consists of three basins, two of them averaging deep, the third averaging and reaching a depth of nearly . The tributaries of Eagle Lake (beginning in the lake's north end and going clockwise) are Cleghorn Creek, Papoose Creek, Merrill Creek, and Pine Creek. Pine Creek is the main tributary of Eagle Lake and is long. Now an intermittent stream; only the upper of Pine Creek has perennial flow. In 1923 the Leon Bly Tunnel was constructed to export lake water to the Honey Lake Valley via Willow Creek, a tributary of the Susan River. The long tunnel was cut through old lava flows but falling lake levels rendered it useless and a landslide partially blocked the tunnel entrance. However, a 1990 study found that lake water still flows through the tunnel although tunnel fish are from the Willow Creek assemblage. Image:Eagle Lake Shoreline 1.jpg|The lake just before dusk. Image:Eagle Lake Shoreline 2.jpg|The lake in the afternoon. ==See also==