The new coin will replace the Susan B. Anthony dollar, which went into circulation in 1979. The U.S. Mint expects the Sacagawea coin to be in circulation by early 2000.
The coin honors the young woman and teen-age mother who accompanied explorers Meriwether Lewis and William Clark to the Pacific Ocean in 1805. Leaders of various Native American tribes attended the unveiling.
"This coin is an excellent way to honor one Indian woman and all Native Americans," said Treasury Secretary Robert Rubin.
Mrs. Clinton said the choice of Sacagawea was a fitting tribute to the heritage and contribution of American Indian women to U.S. culture. "Sacagawea played an unforgettable role in the history of our nation," Clinton said. "Every day this coin will remind us we are a nation of many cultures."
On the new coin, Sacagawea looks over her shoulder directly at the observer. Every other coin in use -- the penny with Abraham Lincoln, the nickel with Thomas Jefferson, the dime with Franklin Roosevelt and the quarter with George Washington -- shows the subject in profile.
In another departure from tradition, her infant son, Jean Baptiste, sleeps on her back. It is the first depiction of a child on a circulating U.S. coin.
The coin itself will be gold-colored and will have smooth edges in order for it to be easily distinguished from the similarly sized quarter, something that was a problem with the Susan B. Anthony. Its metallic composition has not yet been decided.
Glenna Goodacre, the Santa Fe, N.M. artist and sculptor who designed the image of the young Sacagawea, is also well known for her design of the Vietnam Women's Memorial in Washington.
Rep. Rick Hill, R-Mont., said the coin is another example of the importance of the Lewis and Clark expedition to the nation in general and Montana specifically. "This will raise the profile of the expedition as we prepare for the bicentennial celebration," he said. Hill is a co-chair and co-founder of the Congressional Lewis and Clark Caucus.
More images of the coin can be seen at the U.S. Mint's webpage, www.usmint.gov.