Latitudinal transects across subpolar ecozones display striking changes in lakewater chemistry reflecting steep gradients in vegetation, climate, and other variables. This paper explores the relationships among chemical and physical lakewater characteristics of 70 lakes spanning arctic treeline in Canada's Central Northwest Territories. Principal components analysis (PCA) was used to examine trends and relationships among environmental variables and these 70 sites. In general, lakes in this data set were dilute, slightly acidic to slightly alkaline, and nutrient-poor. However, a strong trend toward more concentrated lakewater conditions in densely forested areas was observed relative to tundra regions. Interrelationships among measured limnological variables appear to be strongly influenced by catchment characteristics associated with proximity of sites to treeline.