The US Forest Service, Forest Inventory and Analysis program implements a soil quality indicator which collects and remeasures soils on a 10-year interval. This is one component of its Phase-3 monitoring network, and there is approximately one plot for every 39 000 ha of forest land. The utility of this data is improved when more of the landscape may be assigned a meaningful value. In this study, we used gradient nearest-neighbor imputation techniques to estimate soil carbon stocks in the top 10 cm of soil in the forested part of Great Lake States.