Pygmy Whitefish were collected at Sullivan Lake on 6/30/2025 (n = 25) and 9/23/2015 (n = 39), in order to determine the composition of their diets and the potential for future cohabitation with Bull Trout (Salvelinus confluentus). Contents of each stomach were examined with a dissection scope, and count and length measurements were taken of individuals in each taxonomic group. Dry weights of prey items were determined using published length to weight regression equations. For each fish, we determined the number (and numerical percentage) and weight (and weight percentage) of each taxonomic group in the diet. The data from individual fish were combined to obtain a mean (± SD) numerical percentage (%N) and weight percentage (%W), and frequency of occurrence (%FO) of items in the diet across the population. %FO represents the total percentage of stomachs in which a particular item occurred at least once. These parameters were combined to determine an Index of Relative Importance (IRI) for each food item [i.e., IRI = (%N + %W) x %FO]. Of the 64 stomachs examined, 9 (14.1%) were empty, each one remaining containing at least one food item. Of those that contained food, Chironomidae accounted for 90.7 (± 22.2)%N and 54.5% FO. The frequency of Chironomidae is unsurprising as other investigators determined that Pygmy Whitefish with counts of < 15 gill rakers on the first arch feed almost exclusively on Chironomidae, whereas those with > 15 on the first arch eat comparatively more zooplankton. The mean number (±) SD of gill rakers counted from our samples was 13 ± 1.9 (n = 55).