Boundary Red Mountain Mine. Patented Gold Mine For Sale - USA. Previously Producing Patented Gold Mine for Sale in the USA. $1.6 Billion Estimated & Inferred Resources including 80,000 tons in Mill Tailings. Developed Project with 4 adit tunnels. 1,274,320 Gold ounces estimated. Estimated Monthly NOI of $6.3 Million based on 400 ton/day operation.