In 2004 and 2005, we conducted a Wadeable Streams Assessment (WSA) pilot study in the Tanana River basin, Interior Alaska.  We visited or reconnoitered ~ 175 randomly selected sites falling on blue lines on USGS topographical maps.  Of these, 46 were sampleable; the remaining streams were unsampleable due to dry or non-existent channels, deep incision into permafrost, or unwadeable conditions.  We used this data set to determine what environmental factors regulate benthic macroinvertebrate richness and taxonomic composition in Interior Alaska streams.  Invertebrate taxa richness ranged from 2 to 23.  Elevation and specific conductance ranged from 85 to 2040 meters and 6 to 1388 µS/cm respectively, and were the two best predictors of taxa richness (negatively correlated, pooled r²= 0.55).  Landscape analysis is on-going; we will incorporate watershed scale variables (e.g. geology, permafrost) into these models as they become available.