The issue of global climate change raises a need for information on the management and mitigation of atmospheric carbon dioxide (CO2). The knowledge of carbon (C) characteristics within land resources can be useful for resource managers and policy makers to make informed management decisions. Depending on land use and management, prairie soils can be considered either a source or a sink for atmospheric CO2. Soil sample cores were taken from seven different regions in the north central U.S. Over 1300 samples were analyzed to determine relationships between grassland age and soil organic carbon (SOC) levels. Sample matrices were built to compare restored grassland age classes to adjacent native grasslands and cultivated croplands in the different study regions. The samples were taken at 0-15 cm and 15-30 cm increments and were analyzed for organic carbon, inorganic carbon, and total carbon. Each region was analyzed using regression analysis to calculate SOC sequestration rates for restored grasslands over time. Restored grassland SOC sequestration rates were found to be highly variable throughout the region ranging from annual losses to annual gains of 0.59 ± 1.81 kg m-2 30 cm-1 with an overall sequestration rate of 0.09 ± 1.92 kg m-2 30 cm- 1 • Overall, as average annual temperature and precipitation increased, SOC levels also increased. Under proper management restored grasslands in the north central Great Plains can be managed and used to store atmospheric CO2.