This collection of three manuscripts serves to improve methods for collecting, interpreting, and utilizing autocorrelated data from headwater stream networks. Two chapters of this work relied on a unique and comprehensive set of data which constitutes a complete census of habitat unit fish counts from 40 randomly selected headwater basins in western Oregon. The first objective of this work was to evaluate how different sampling designs captured spatial autocorrelation, given the samples were drawn from a population of spatially autocorrelated observations. The second objective was to investigate spatial autocorrelation model range parameters as measures of patch sizes. The third objective was to refine the analysis of temporally autocorrelated hydrology data from paired watershed studies. These  are used to evaluate forest harvesting effects on stream biota and hydrology (i.e. fish, amphibians, insects, stream flow, and sediment yield).