The scope of the review for this memorandum included:

• a comprehensive review and classification of underground stoping methods which may be applicable as an alternative to block caving;
• a review of literature to estimate an Operating Cost per ton (or per tonne) for the more feasible alternatives to block caving;
• a review of other pertinent block caving operations world-wide;
• a meeting with RCM personnel (Mses. Vicky Peacy and Kim Heuther, and Mr. Bill Hart) on 3/23/17 to discuss information needs to complete this assessment;
• develop an estimate, based on limited information provided by RCM, of the total tons of potentially mineable material above a cut-off grade of 2% which lies at or above the -2,500 ft level;
• project the tons vs cut-off grade (COG) line to other COGs to estimate the tons available if the COG were to rise due to utilizing a more expensive alternative mining method; and
• discuss possible realistic alternative mining methods which may be utilized instead of block caving.