July 27, 2002
Tour Guide: Dr. Jeffrey Kershner, USDA Forest Service Research Scientist, USU Department of Aquatic, Watershed and Earth Resources
Bear Lake/St. Charles Creek Fact Sheet
-Bear Lake is an oligotrophic natural lake bisected by the Idaho-Utah border.
-The lake is 32 km long and 6-13 km wide with a surface area of 282 km2 at full pool. It has a mean depth of 28m and a maximum depth of 63m.
St. Charles Creek
-St. Charles Creek is a second-order stream that splits and flows into the northwest and north end of the Bear Lake. St. Charles Creek is 14.4 km long and flows in an eastern direction out of the Bear River Range.
-St. Charles Creek has probably historically been the main source of cutthroat trout reproduction due to its long length, potentially abundant spawning and rearing habitat and sufficient discharge.
-There are seven irrigation diversions on St. Charles Creek of which only two are screened. During drought years, more water is allocated than available and irrigation water-use dries up most of the lower reaches of the creek.
-Approximately one-half mile before it reaches the town of St. Charles, the creek splits into two creeks: the Big Arm, which flows to the north and the Little Arm, which flows to the South. During the early 1900's, a road that crosses the north shore severed the connection of the Big Arm to Bear Lake. In 1996, IDFG and PACIFICORP reconnected the Big Arm to the lake and added a fish ladder to allow fish to migrate into the Big Arm.
-Species present in all or parts of St. Charles Creek include, Bonneville cutthroat trout, rainbow trout, brook trout, mottled sculpin, Bear Lake sculpin, speckled dace, longnose dace, redside shiner, Utah chub, Utah sucker, mountain sucker, green sunfish, yellow perch and common carp.
-A major factor in the initial decline of cutthroat trout in Bear Lake was overfishing at the beginning of the century. The wild run of cutthroat trout in St. Charles Creek was thought to be extinct by the early 1900's. Habitat degradation from irrigation diversions was also influential in the decline of the Bear Lake cutthroat and probably limited population recovery.
-The current population of wild cutthroat in the lake is small. Fewer than 100 wild fish moved up St. Charles Creek to spawn during the spring of 2000 and the number of spawninq fish rarely exceeds 500.