The Valley

The Anaconda Copper smelter deposited arsenic, lead, and sulfur dioxide across hundreds of square miles of Montana for decades. Ada finds the company's own environmental survey from 1902 — the year the smelter opened — documenting the projected contamination radius and its effect on humans. The survey was used internally to negotiate land purchase prices before contamination became visible. Every parcel in the contamination zone was purchased below market value in a 14-month window.