Salinity is a fundamental component of all estuarine environments, affecting water chemistry and density-driven flow dynamics. In the Snohomish River Estuary in Washington State, saltwater from Possession Sound and freshwater from the Snohomish River stratify, forming a partially-mixed salt-wedge estuary. Haloclines, zones of rapid salinity-change, vary in depth depending on season, temperature, and freshwater influx. Above and below the halocline, the water column displays relative homogeneity in salinity. An established relationship between tide height and salinity may allow researchers to use accessible tide data as an indicator of salinity. If such a relationship were to change, any difference from the baseline relationship may be used as a measure of change in the ecosystem to track climate change and other factors. I examined salinity data collected throughout the water column, at surface, halocline, and deep zones, to detect the influence of tides on salinity. I anticipated increased tide height, paired with corresponding saltwater encroach, to correspond to an increase in the salinity of brackish water at the halocline. I expected surface and deep zones would be relatively unaffected, owing to their separation from this immediate area of change. I predicted any relationship between tide height and salinity to strengthen with increased distance from the Snohomish River, as saltwater would be less diluted by freshwater, implying a more noticeable influence on it. My analysis of readings taken at field sites in Possession Sound from 2017-2020, restricted according to site and season, did not present any consistent correlation between degree of tide-salinity correlation and distance from the Snohomish river. I detected varying correlation between salinity at restricted depths and tide height. Further research will entail further elimination of confounding variables.