The Sacagawea Dollar, issued by the United States Mint, was introduced in 2000 and features a depiction of Sacagawea, a Shoshone woman who assisted Lewis and Clark on their expedition. The coin is made of a bi-metallic composition, with a golden hue, and has become a popular collectible, particularly for its historical significance and artistic design. The 2015 Sacagawea Dollar is part of the series that honors the contributions of Native American women. Collectors often seek out specific years and mint marks to complete their collections, making these coins sought after in the numismatic market.