This paper presents a spatially explicit analysis of the nutrient retention ecosystem service responses to changes in forest management in the White River Basin (WRB), Indiana. We use a modified version of the Integrated Valuation of Environmental Services and Tradeoffs (InVEST) model and ArcGIS to simulate and value the magnitude of nutrient retention service, assess the prediction power of the InVEST water yield and nutrient retention model, estimate changes in the quantity and value of nutrient retention service with hypothetical increases in enrollment in a forest conservation program, the Classified Forest and Wildlands (CFW) Program, and rank candidate scenarios using a conservation return on investment (ROI) measure. The results suggest that the benefits from a single ecosystem service of nutrient retention can exceed the cost of the tax deductions for both forest conservation scenarios considered but not for the current CFW enrollment. In particular, expanding the CFW program in contaminated sub-watershed yields a higher ROI than expanding the CFW program along river forks. Consequently, substantial savings can be achieved by applying the ROI analysis to guide conservation policies, compared to prioritization merely on the quantity measures of nutrient retention service or compared to program expansion that is not spatially targeted.