Tally lake

Fished several lakes in Montana for lake trout but never tried Tally.  Did some research and found that it was planted with Lewis Lake strain lake trout twice in the mid 80's.  Current rule is one fish over 42", state record was 42 1/2".  Fish and game says no reproduction so fish are all 30 years old except for a few that come up from Stillwater. Gillnet samples for all species show limited fish. Have bathymetric map and almost no structure with steep banks to 450'.  Does anybody know if it is worth a several day trip for c/r fishing or is the lake trout population very limited?  Thanks for any insight.