Rapid urbanization enhances the desirability of policies for preserving open space but policies intended to preserve open space may extend the urban boundary and create leapfrog development. We investigate this potential conflict between open space preservation and urban sprawl conceptually and empirically using data from the Baltimore-Washington suburbs. In accord with previous theoretical and empirical results, the estimated econometric model indicates that both zoning and forest planting requirements contribute to sprawl by increasing the amount of land needed to accommodate the current number of households. These results point to a conflict between preserving open space incorporated into private building lots or internal to sub-divisions and public open space at the urban fringe.