This work addresses the introduction of renewable ammonia plants with hydrogen obtained from wind-powered electrolysis into a region's ammonia supply chain. A supply chain optimization problem is fomulated to decide where to build new renewable plants, how large they should beand how much ammonia should be transported between conventional plants, renewable plants, distribution centers, and demand centers to meet local demand. A multiobjective optimization problem is also formulated to analyze tradeoffs between economic and environmental objectives. The developed framework is applied to a case study in Minnesota utilizing cost data from a pilot renewable plant in Morris, MN. The base case establishes that it is economically optimal to build a single new renewable plant that supplies 27% of the state's ammonia. New renewable plants are selected for construction in 48% of Monte Carlo trials. A carbon tax analysis is also performed to analyze the carbon emissions of the supply chain. The analysis shows that a modest carbon tax of just $35/t cuts emissions by 65% and promotes the construction of 3 new renewable plants.