Elevated chloride concentrations in streams can affect aquatic life and recent studies suggest salinization of freshwaters due to long-term road salt use. Yet, relationships between urbanization and chloride concentrations are not clear. Here we report on chloride concentrations from three sites within the Jack’s Defeat Creek watershed in central Indiana. Chloride concentrations were measured routinely beginning in September 2007. The sites vary in size and land use. Site 1 (4.8 sq km) drains a residential area and had significantly lower baseflow chloride concentration (mean = 14.3 mg/L) than Site 2 (17.4 sq km) or Site 3 (27.2 sq km), both of which contain urban and commercial areas (baseflow means of 22.2 and 25.4 mg/L, respectively). Intensive sampling during fall and winter storms in 2007 revealed chloride concentrations > 260 mg/L. Run-off of road salt fluctuated daily in relation to air temperature, and stream chloride concentrations often varied 10-fold or more in a 24-hour period. During storm run-off, chloride increased at all stream sites regardless of land use, although the highest chloride concentrations always occurred in the more urbanized sites. Elevated baseflow concentrations suggest salinization of groundwater may be occurring in the more developed areas of the watershed.