2006-S South Dakota Proof

The 2006-S South Dakota clad proof quarter delivers Mount Rushmore as John Mercanti composed it: four frosted presidential faces emerging from the Black Hills granite, flanked by a ring-necked pheasant in flight and a stalk of wheat below. The inscription "Great Faces. Great Places." sits beneath the monument, leaning into the state's tourism identity rather than its statehood history, which is November 2, 1889, alongside North Dakota in the same federal proclamation. Mercanti, who would later design the obverse of the American Silver Eagle, handled Rushmore with restraint, letting the four faces carry the composition while the pheasant adds movement and the wheat anchors the agricultural reality of the state's economy. In proof format the granite texture of the carved faces holds distinct frosted detail against deep mirrored sky, with each president's features readable in a way the business-strike version softens.

San Francisco struck 2,882,428 of these clad proofs for the 2006 Proof Set, the standard run-length applied across all five state designs that year. Authentication starts with the mirrored fields, which on a genuine proof show watery, hall-of-mirrors reflectivity from polished dies striking polished planchets at elevated tonnage. The rims are squared from a close collar, not rounded like business strikes. Under a 10x loupe, die-polish lines run in consistent parallel directions across the open fields, while scattered hairlines indicate post-strike cleaning. Radial flow lines moving outward from the center mark a prooflike business strike rather than a true proof, since the multiple-strike proof process eliminates those single-strike metal-flow patterns. The cupronickel-clad alloy holds at 5.67 grams and 24.3 millimeters, with the copper core visible as a thin reddish line along the reeded edge. Cameo and Deep Cameo designations from PCGS and NGC carry significant premiums, with DCAM examples consistently bringing the strongest prices on this issue.

For how the 2006 releases fit into the eleven-year State Quarter run and the parallel proof program, see the 50 State Quarters series history.