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was located only a few miles below a suspected spawning site. It may also indicate that many larvae shifted to migrational rather than drift behavior. Phis shift may occur in larvae over 11 mm, which were seldom collected in the drift, but were collected in backwater habitats in the summer nursery habitat sampling (Trammell and Chart 1998). Drift densities at Loma and Moab, separated by over 160 km, were more closely correlated (rz = 0.55) than LomalWestwater or Westwater/Moab. The strength of the LomalMoab relationship was due to the highest drift densities for both sites occurring in 1995, but the remaining years were indeterminate. 1995 was the highest flow year, which suggests that high flows may stimulate increased spawning efforts and larval production on those reaches. Drift densities were 3'~ highest in 1993 at both sites. The low flow years (1992 and 1994) ranked 4`~ and 5~'', respectively at Moab and 2"~ and 4`'', respectively at Loma. The lowest drift density at Loma and the highest drift density at Moab occurred in 1996, the intermediate flow year. Since the intermediate flow year did not produce intermediate larval densities, some non- related flow variable appears to have affected larval production in the Loma and Moab reaches that year. This result could have happened if spawning was heavier downstream of Westwater and lighter upstream of Loma in 1996. However, it is assumed that adult spawning density and distribution is fairly consistent between yeazs. Whatever the cause, the 1996 data strongly suggest that larval densities measured in Moab can vary independently of larval densities upstream at Loma, although similar annual trends in four of the five years indicate similar responses to environmental conditions. Catch rates in fish/1000 m3 were substantially higher at Moab than at Westwater for all years, and higher than Loma in four of the five years. The exception was 1994, which was a poor year for Colorado pikeminnow larval drift density at both sites, and a poor year in regazd to flow conditions conducive to transport larvae via a passive drift. Total transport abundance also was higher at Moab than at Loma or Westwater for all five years, which suggests substantial spawning taking place below Westwater. Similar annual trends in Colorado pikeminnow drift and higher densities at Moab than Loma suggest that larvae produced in Colorado may also contribute to larval numbers sampled in Moab. However, since the Westwater data do not support a progressively increasing downstream drift and since there are opposing results between study sites in 1996, river wide trends were not strongly apparent. 16