Phase 1 – All major tributaries to the Kootenai River in Idaho and Montana will be sampled for YOY rainbow trout during the last two weeks of September and into the first two weeks of October 2014.  Tributaries in Idaho that will be sampled include: Boulder Creek, Curley Creek, Caboose Creek, Debt Creek, Katka Creek, Moyie River, Cow Creek, Deep Creek (and tributaries), Myrtle Creek (and tributaries), Burton Creek, Flemming Creek, Ball Creek, Rock Creek, Trout Creek, Fischer Creek, Mission Creek, Parker Creek, Long Canyon Creek, Smith Creek and Boundary Creek (and tributaries).  Waters in Montana that will be sampled include: the Kootenai River (Libby Dam tailrace), Dunn Creek, Fisher River (below Wolf Creek), Wolf Creek, Fisher River (upstream of West Fisher), Libby Creek (Below Big Cherry Creek), Big Cherry Creek, Libby Creek (upstream of Swamp Creek), Flower Creek, Parmenter Creek, Pipe Creek, Bobtail Creek, Cedar Creek, Quartz Creek, O’Brien Creek, Lake Creek (upstream of the falls), Lake Creek (downstream of the falls), the Yaak River (downstream of the falls), and the Yaak River (upstream of the falls.  All YOY trout will be collected a minimum of one kilometer (when possible) from the confluence with the Kootenai River to ensure that the strontium isotopic signatures of each particular tributary will not be confounded by transitional movement (of fish)between tributary and mainstream river.  Attempts will be made to collect ten YOY rainbow trout from each tributary, five of which will be used for strontium isotope analysis; extras will be used, as needed.  In addition, ten adult rainbow trout will be collected from each of the following areas of Kootenay Lake, British Columbia:  North Arm, South Arm, West Arm and the delta.  Strontium signatures from these lake fish will establish baseline Sr levels for the lake (relative to the Kootenai River).

Phase 2 – Adult rainbow trout will be collected from the mainstem Kootenai River during August and September 2014 using boat electrofishing and angling.  Rainbow trout will be collected from directly below Libby Dam, Montana to the Idaho/British Columbia Border (Figure 1).  Fish sampling in the Montana portion of the Kootenai River will occur within four sections located at the following river kilometers: 351.1 to 356.7, 343.0 to 346.1, 323.5 to 328.2 and 295.7 to 299.6 (Figure 2).  Montana FWP selected these sites because they coincide with long term population monitoring sections on the Kootenai River, and are the location of a detailed rainbow trout mark-recapture study intended to estimate growth and survival.   Montana FWP will randomly collect 50 adult rainbow trout from each of the four sections (200 samples total) for strontium isotope analysis.  Sampling sites in Idaho will be located approximately 10 km apart, beginning at the Idaho/Montana border and extending to the Idaho/British Columbia Border (Figure 3).  Sites will be chosen such that they occur between two tributaries that were sampled for YOY rainbow trout, resulting in a total of 15-20 sites being sampled.  A target of five adults will be collected at each site, resulting in a total of 75-100 adults being collected for strontium isotope analysis.  If the appropriate sample size cannot be achieved via boat electrofishing, angling will be used secondarily to target adult rainbow trout.