Sun Valley Legacy Estate & Development Masterpiece. Discover the pinnacle of mountain living at 120 Keystone St, a premier 52-acre legacy estate in the exclusive Elkhorn area of Sun Valley, Idaho. This rare dual-parcel landholding (18.6 & 33.5 acres) offers a breathtaking canvas for a private horse property or a high-end boutique residential development. Search address on YouTube for video tours. The Ultimate Equestrian & Outdoor Retreat: Bordering U.S. Forest Service land, the estate provides unparalleled private canyon access for horseback riding and hiking. Secure your legacy with senior 1883 water rights (irrigation/stock) and a high-yield well. The property features a serene pond with on-site geothermal potential, creating a year-round alpine oasis for wildlife and residents alike. Developer Upside & Infrastructure: Zoned BC/R-10 with patented mining claims, the land is ready for a luxury compound or multi-homesite project. Utilities (well, septic, buried power) are already installed. Significant value-add opportunities exist through a potential 18-acre USFS land swap, and recent analysis indicates potential for a third building site, offering even greater density and investment value. Strategic Opportunity: Located minutes from Ketchum and Sun Valley Resort, this $10.5M-appraised asset is offered with flexible acquisition options. Owner will carry paper for up to five years with 50% down; other terms are negotiable. Control one of the last large private holdings in a supply-constrained market.