100 Pesos Tamaulipas - Gold and Silver Proof Issue

This piece belongs to Mexico's long-running "Estados Unidos Mexicanos" series celebrating individual states, a program the Casa de Moneda launched in 2003 and extended across multiple annual tranches. Tamaulipas, a northern border state whose economy has historically straddled formal trade and contraband routes along the Gulf coast, received its commemorative issue in the 2007 tranche alongside several other states. The bimetallic proof format — .999 gold core seated in a .999 silver ring — was an unusually fine specification for a circulation-commemorative hybrid, placing these well above the bullion-grade bimetallics common to the broader Latin American market at the time.