Mathematical programming is used to examine the economic potential of greenhouse gas mitigation strategies in U.S. agriculture and forestry. Mitigation practices are entered into a spatially differentiated sector model and are jointly assessed with conventional agricultural production. Competition among practices is examined under a wide range of hypothetical carbon prices. Simulation results demonstrate a changing portfolio of mitigation strategies across carbon prices. For lower prices, preferred strategies involve soil and livestock options; higher prices, however, promote mainly afforestation and biofuel generation. Results demonstrate the sensitivity of individual strategy potentials to assumptions about alternative opportunities. Assessed impacts also include market shifts, regional strategy diversity, welfare distribution, and environmental co-effects.