The purpose of this report was to evaluate baseline loadings of nutrients and sediment to the Mississippi River from the state of Illinois and to identify the sources of those loads. The Illinois EPA's Ambient Water Quality Monitoring Network was selected as the data set to conduct this analysis because it provided a statewide network with consistent sampling and analysis methods over an extended period of time. Parameter selection included nitrogen measured as total ammonia-N, total nitrate+nitrate-N and total Kjeldahl nitrogen, total and dissolved phosphorus, total suspended solids and stream flow. To determine loads and yields, total ammonia-N and total nitrate+nitrite-N were added together as inorgnic nitrogen. Nitrates and total Kjeldahl nitrogen were added together to determine total nitrogen. For this report, baseline loads were determined from the mean load calculated from the samples collected over the period of record. Baseline yields were determined by dividing the baseline load by the drainage area.