U.S. Mint website (http://www.usmint.gov/mint_programs/nativeamerican/):
In 2009, the United States Mint began minting and issuing $1 coins featuring designs celebrating the important contributions made by Indian tribes and individual Native Americans to the history and development of the United States. The Native American $1 Coin Program is authorized by the Native American $1 Coin Act (Public Law 110-82).
The obverse (heads side) design retains the central figure of the "Sacagawea" design first produced in 2000 with the inscriptions LIBERTY and IN GOD WE TRUST. The reverse (tails) design changes each year to honor an important contribution of Indian tribes or individual Native Americans with the inscriptions $1 and UNITED STATES OF AMERICA. Reverse designs for the Native American $1 Coin are selected by the Secretary of the Treasury after consulting with the U.S. Senate Committee on Indian Affairs, the Congressional Native American Caucus of the U.S. House of Representatives, the Commission of Fine Arts and the National Congress of American Indians, and after public review by the Citizens Coinage Advisory Committee. Like Presidential $1 Coins, Native American $1 Coins have a distinctive edge, are golden in color, and feature edge-lettering of the year, mint mark and E PLURIBUS UNUM.
During the years of the program that correspond with the Presidential $1 Coin Program, Native American $1 Coins will be issued, to the maximum extent practicable, in the chronological order in which the Native Americans depicted lived or the events recognized occurred. Following the conclusion of the Presidential $1 Coin Program, the Native American $1 Coin Program coins will be issued in any order determined to be appropriate by the Secretary of the Treasury after consultation with the U.S. Senate Committee on Indian Affairs, the Congressional Native American Caucus of the U.S. House of Representatives, the Commission of Fine Arts and the National Congress of American Indians, and after public review by the Citizens Coinage Advisory Committee.
The 2009 Native American $1 Coin reverse commemorates the spread of Three Sisters Agriculture around 1000 A.D. and features a Native American woman planting seeds in a field of corn, beans and squash. The 2010 Native American $1 Coin reverse commemorates the Great Tree of Peace and the Iroquois Confederacy of the early 1400s, and features an image of the Hiawatha Belt with five arrows bound together and the additional inscriptions HAUDENOSAUNEE and GREAT LAW OF PEACE. The 2011 Native American $1 Coin reverse commemorates the Great Wampanoag Nation and the creation of an alliance with settlers at Plymouth Bay in 1621 and features the hands of the Supreme Sachem Ousamequin Massasoit and Governor John Carver, symbolically offering the ceremonial peace pipe after the initiation of the first formal written peace alliance between the Wampanoag tribe and the European settlers. The additional inscription is WAMPANOAG TREATY 1621. The 2012 Native American $1 Coin reverse commemorates the Trade Routes that helped spread the horse in 17th Century, and features a Native American and horse in profile with horses running in the background. The 2013 Native American $1 Coin commemorates the Delaware Treaty of 1778. Its reverse design features a turkey, howling wolf and turtle (all symbols of the clans of the Delaware Tribe), and a ring of 13 stars to represent the Colonies. The design includes the required inscriptions UNITED STATES OF AMERICA and $1. The additional inscriptions include TREATY WITH THE DELAWARES and 1778.