Understanding when, where, and how nitrate is exported from watersheds is the key to addressing the challenges that excess nutrients pose. We analyzed daily nitrate and streamflow data for five nested, agricultural watersheds that export high levels of nitrate over a 4-year time period. Nutrient export patterns varied seasonally during baseflow but were stationary during stormflow. Additionally, anthropogenic and geologic factors drove nutrient export during both baseflow and stormflow.