THOMPSON LAKES 



The Thompson lakes are a series of three lakes connected by shallow water ways. Although the 

 channels that connect the lakes arc passable to fish, the lakes will be considered as separate 

 management units for the purposes of this document. 



LOWER THOMPSON LAKE 



Tjikpn<>sfriptinnt 



Lower Thompscm Lake is a medium-sized lake that is the most downstream of the chain of TCL. 

 It is the source of the Thompson River which flows into the Clark Fork River. The channel that 

 connects Lower Thompsai Lake to Middle Thompson Lake is fairly wide and of sufficient depth 

 to pass fish. The lake has a maximum depth of 140 feet and a surface area of 240 acres (Figure 

 4). Between March 1, 1993 and February 28, 1994, FWP estimated that as many as 2,538 

 anglCTS, of which 98 percent wctc Montana residents, fished at Lower Thompson Lake (Montana 

 Statewide Angling Pressure Report). 



Tjikp Managpmftnf Status: 



Management of Lower Thompson Lake commenced in 1930 when 150,000 cutthroat trout were 

 planted. Between 1930 and 1992, various stocking options were exercised and generally reflected 

 hatchery sources of fish and angler preferences (Table 4). Early inventories of the lake showed 

 native species assemblages that included westslope cutthroat trout, bull trout, mountain whitefish, 

 northern squawfish, largescale suckers, longnose suckers, and redside shiners (bull trout 

 apparently existed at very low levels and have not been found in recent inventories). 



By 1953, unauthorized introductions established populations of largemouth bass (which currently 

 account for most of the fishing pressure in the lake), yellow perch, and pumpkinseeds in the lake 

 system. Northern pike were illegally introduced to Upper Thompson Lake prior to 1965 and are 

 self-sustaining and expanding their range. A few northern pike have been reported in Lower 

 Thompson Lake. The long-term status of this species is uncertain. 



Between 1954 and 1959, FWP attempted a partial eradication program to reduce yellow perch 

 populations. Several yellow perch spawning and rearing areas in Lower Thompson Lake were 

 poisoned to create more space for cutthroat trout. In addition, FWP liberalized whitefish daily 

 and possession limits for the same reason. The program failed and was discontinued after 1959. 



Lower Thompson Lake was also planted with kokanee in 1951 and 1952. These plants, along 

 with kokanee plants in Middle Thompson Lake and Upper Thompson Lake, were likely the 

 ancestors of the kokanee population that exists today in Middle Thompson Lake. In the mid- 

 1980s, soon after Flathead Lake, Whitefish Lake, and McGregor Lake kokanee populations 



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