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distributions between the marked and captured portions of the population, it is appropriate to, stratify the data into one or more length categories to reduce bias in the abundance estimate (Bernard and Hansen 1992). In addition, we searched for significant differences in mark rate among the three geographic strata. We found no significant difference (x2 = 2.53, df = 2, P = 0.28) in the mark rate among the Salt, Coyote and Boulders reaches (Table 6). Upon further testing, we found that there was not a significant difference in the mark rates among the three sub-reaches within each reach (x2 = 13.43, df = 8, P = 0.098). The above tests suggest it was not necessary to stratify the data by geographic reach to obtain an estimate. The optimal length stratification is found by choosing length boundaries in a contingency table of unmarked and marked fish (e.g., Table 5) that maximizes the homogeneity in mark rate among length groups (Seber 1982, Bernard and Hansen 1992)., When this procedure was performed, it was found that the optimal stratification occurred at 250 mm (x2 = 15.47). This means that independent estimates were produced for HBC from 150 to 250 mm and for HBC > 250 mm (Table 7). The resulting and preferred summed estimate for HBC ~ 150 mm is 2,334 fish (SE = 411). Table 8 and Figure 11 show this estimate as compared against historical estimates. Since the Recovery Goals for HBC (USFWS 2002) focus on abundance estimates of fish ~ 200 mm (i.e., 4+ year old adults; USFWS 2002), estimates are presented relating to their abundance. First, the data set was truncated to include only fish ~ 200 mm. During April, 184 unique HBC ~ 200 mm were marked [M]. During May, 229 unique HBC ~ 200 mm were captured [C], and 28 unique HBC ~ 200 mm were recaptured [R]. The smallest HBC recaptured [R] had a total length of 200 mm, and the largest recaptured was 385 mm in TL. Using two-tailed Kolmogorov-Smirnov tests, the cumulative length distribution of marked [M] HBC was significantly different from captured [C] HBC (n1 = 184, n2= 229, Z = 2.491, P < 0.001). Likewise, the cumulative length distribution of marked [M] HBC was significantly different than recaptured [R] HBC (n1 = 184, n2 = 28, Z = 2.247, P < 0.001). The typical conclusion drawn from these test results is that there was significant size selective sampling during both the marking and recapture events (Bernard and Hansen 1992), or that stratifying the data by length to obtain an estimate is desirable. The optimal stratification occurred at 250 mm TL (Le., independent estimates were produced for HBC <251 and for HBC > 250). The resulting pooled estimate was 1,763 fish (SE = 398). However, because it should result in less bias to use the entire data base rather than truncating it (Seber 1982), the Chapman modified Petersen estimate of HBC ~ 150 to 250 mm (984 fish; see Table 7) was multiplied by the proportion offish from 200 to 250 mm, providing an estimate of 467 fish in the 200-250 mm category. This abundance estimate was then summed with the Chapman modified Petersen length stratified abundance estimate of 1,349 fish >250 (see Table 7). The resulting, and preferred estimate for HBC > 200 mm was 1,816 fish (SE = 397). Table 9 and Figure 12 show this estimate as compared against the spring estimates for the past three years. 21