This paper describes the design for the stabilization and the closure of the Detroit Salt Mine which includes design of the stabilization measures in the mine to ensure long term mine stability, and concrete plugs in two mine shafts to prevent long-term leakage into the mine and subsequent solutioning of the salt. The design includes grouting in the mine at two floor levels, grouting in and around the shaft plugs including two-stage cement and chemical curtain grouting in the rock surrounding the plug and high pressure contact grouting at the concrete-soil and concrete-rock interface. The paper addresses the selection of plug locations, plug geometry, concrete mix design, cooling of the concrete and grouting of the rock and rock/concrete interface. Lack of proper maintenance and repair during the life of the 90-year old facility and an aggressive subsurface environment, presented many unusual design issues. The paper describes how the mine stabilization and closure design addressed the issues and ensured that ground water was controlled at all phases of the construction.