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notIceably (Figure 5; Appendix A, Table A-I). The greatest percentage of northern pike captured in each year were in the 550 to 750 mm size group (66% overall). Using the 600-650 size classes as a reference point, the distribution of northern pike sizes shifts toward more fish ~6oo mm in length from 1986-88 to 1989. In 1990 the peak of the distribution becomes more pronounced at the median of 600-650 rom with increases in that size group and decreases in both smaller and larger fish. In 1991 this distribution pattern is maintained, but is also accompanied by relative increases in fish in the 700-750 mm and 250-400 rom size classes. It is possible that the relatively large number of northern pike in the 350-500 mm size group observed in 1989 resulted in the more pronounced peak in northern pike numbers in the 550-650 mm size group in 1990, and the subsequent increase in northern pike numbers in the 650-750 mm size group in 1991. The length frequency distributions shown in Figure 5 were summarized into 4 size groups to facilitate analysis of these changes through chi-square analysis (Table 2). Using expected frequencies derived from a mean distribution from all the empirical data, statistical results showed the changes in length frequency distribution over the four time periods were highly significant. Examination of the relative contribution of the summed year and size group cells to the chi-square statistic showed that changes in the smallest and largest northern pike size groups and changes in the frequency distributions of northern pike collected in 1986-88 and 1989 contributed most to the chi-square statistic. This is generally consistent within the 16 individual cells as well. Length frequency distributions of northern pike between river reaches demonstrated a strong, unimodal distribution in the Craig reach and a slight lateral shift in northern pike sizes toward larger fish among the downstream river reaches (Figure 6; Appendix A, Table A-2). The distributions indicate most of the smaller northern pike were collected from the Craig reach. Using the 400 nun and 350 nun size groups as reference points, 37 of 49 (76%) and 26 of 27 (96 %) of northern pike in these size groups came from the Craig reach. Looking at the larger size groups of northern pike ~751 rom in length, 30 of 65 (46%) were collected in the Craig reach, and 16 of 65 (25%) were collected in both the Maybell and Lily Park reaches. Larger northern pike appeared very rarely in the Juniper reach. Using the same approach for chi-square analysis of length frequency distributions of northern pike by river reach, the differences noted between the four reaches were also significant (Table 3). Relative contribution to the chi-square statistic was greatest for changes observed in the smallest and largest size groups of northern pike, especially in the Juniper and Lily Park reaches. The same trend was noted for the size groups in the Maybell reach, but their relative contribution was small. Length-weif!ht relationship Log-log length-weight regressions were calculated for northern pike samples by year and by river reach (Table 4). All regressions resulted in R-square values of 0.930 or greater. Using the X coefficient as the index of proportionate growth and a value of 3.00 for this coefficient as demonstrating weight gain in equal proportion to increase in length, northern pike samples by year showed annual changes. In 1986-88, northern pike showed lesser weight gain with 17