Sampling by seine and fish processing procedure followed in 1998 was essentially identical to that in 1997 (Maslin, et al., 1997). In addition, we used electrofishing as a supplement to seining in some sites with dense cover. The upstream and downstream ends of the site were first blocked with seines, then a Smith-Root model 12 backpack electrofisher was fished systematically from downstream to upstream with as many as five passes taken and depletion analysis used to calculate population within the site. Before fishing the site, ambient water conductivity was measured, settings were adjusted for voltage, frequency, and pulse width based on experience, then a sample area outside the site was fished and parameters fine-tuned. Because of its inefficiency (see discussion), only a few sites were sampled by electrofishing. Because Mud Creek was readily accessible everywhere throughout the reach utilized by rearing juvenile chinook, it was chosen for intensive sampling, while other creeks were sampled fewer times. The intent was to use Mud Creek as a model for interpreting the data in other tributaries. The unusually wet year in 1998 forced us to modify our plans. Mud Creek was often difficult to sample quantitatively and larger streams such as Thomes and Pine, were impossible to sample. We compensated for the high water limitations by spending more time than intended documenting upstream distances and presence in some of the smaller streams. DNA Sampling Tissue samples were taken from 72 juvenile chinook (of winter-run size or near winter-run size) from Mud Creek. Two approximately 1 square mm bits of caudal fin were snipped with micro-scissors and placed into separate numbered vials. The vials were kept on ice until we got back to the laboratory, where they were placed in a -70š Freezer for storage. At the end of the sampling season, the vials were packed in an insulated chest with dry ice and transported to the Bodega Bay Marine Laboratory for race analysis based on microsatelite DNA. (Banks, et al. 1996).