The Stibnite project is located in the remote central Idaho Rockies near the town of Yellow Pine.  It is a brownfields gold-antimony project featuring three open pits and an anticipated 22,000 tpd plant throughput, along with challenging terrain and environmental constraints. Tierra Group completed the preliminary feasibility design for the proposed tailings storage facility, water diversions, and site-wide water management, including relevant content for the NI-43-101-compliant prefeasibility technical report. Tierra Group also completed TSF and water diversion designs and completed reclamation cost estimating for a NI 43-101 compliant feasibility study published in January 2020. Tierra Group also completed engineering analyses and design for federal and state permitting.

The TSF was lined with a composite geosynthetic liner system. A rockfill buttress was built in multiple stages during project development. Diversions redirected a perennial mountain stream around the TSF. Tierra Group continues supporting Midas by completing detailed design and permitting support.