Snohomish County used this funding to complete the study, “Primary Sources of Fine Sediment in the South Fork of the Stillaguamish.”. The work completed included 1) collecting fine sediments in artificial redds in known spawning areas of the SF Stillaguamish Rivers and tributaries and characterizing the timing of delivery and physical characteristics, 2) characterizing the known and suspected sources of fine sediment, 3) sampling Total Suspended Solids in the water column to connect sources and redds, and 4) identifying and ranking sources according to the amount of fine sediments they are delivering to redds during the time that juvenile or eggs are in the gravel. The study was explicitly and specifically designed to provide the basis for ranking individual sediment sources for treatment based on their contribution to decreased survival of ESA-listed juvenile Chinook salmon. A ranked list of sources and recommended capital projects was the final project deliverable. ESA-listed Stillaguamish Fall Chinook salmon populations are at extremely low numbers. Technical experts and habitat model runs (Ecosystem Diagnosis and Treatment) indicate that juvenile survival is limiting production, and that fine sediment intruded into redds, causing suffocation and/or entombment, is a major source of juvenile mortality. Expensive, difficult and time-consuming sediment reduction projects are partly addressing likely sources of fine sediments, but it is unknown if these efforts will be sufficient to significantly increase juvenile survival. This had been identified as a data gap in the Stillaguamish Lead Entity Strategy.