In May 2000, while looking through a roll of Sacagawea Dollars, collector Frank Wallis of Mountain Home, Arkansas made an astonishing discovery. He found a coin with the reverse of a Sacagawea Dollar and the obverse of a Statehood Quarter. This type of mint mistake, known as a “mule error,” combines obverse and reverse designs not intended to be paired together.
The 2000 Sacagawea Dollar Mule Error has the diameter, weight, and composition of a typical Sacagawea Dollar. It was later determined that the error was created when someone in the die room at the mint mistakenly provided a Statehood Quarter obverse die for the Sacagawea Dollar. Soon after striking, the mules were discovered in the coin bin and ordered destroyed. Nonetheless, some examples managed to escape the mint. Following the initial discovery, additional specimens were located through regular circulation channels. Curiously, three different die pairs have been identified among the discoveries.
To date, 19 different examples of the 2000 Sacagawea Dollar Mule Error have been confirmed. Pieces have sold at auction for prices in the low six-figures.