As part of the promotional activities leading up to the launch of the new series, the United States Mint partnered with General Mills to include 5,500 of the new “Golden Dollars” in boxes of Cheerios cereal. It would later be discovered that some of the 2000 “Cheerios” Sacagawea Dollars (Buy on eBay) featured a prototype reverse design that was different from the final design used for full scale production.
The discovery was not made until 2005, when close examination of the coins revealed differences in the tail feathers of the eagle. On the prototype reverse (shown above at left), there is a central line apparent and a greater level of detail in the feathers. On coins produced for circulation (shown above at right), the central line is recessed and there is considerably less detail. The modification was made prior to production for circulation in order to create a more realistic rendering of the tail feathers.
The 2000 “Cheerios” Sacagawea Dollar is considered to be a true pattern, and pieces are difficult to find. Research has determined that not all of the 5,500 pieces distributed within the cereal boxes had the prototype reverse. Furthermore, because the coins were distributed broadly to the public and the rarity of the pieces was not discovered until years later, many of the coins were presumably spent into circulation or otherwise misplaced.
In late 2008, one of the pattern dollars was actually discovered in circulation by someone searching rolls of small sized dollars. Other pieces may still be in the hands of the original recipients who have no idea of the true value of the coins. Altogether, the major grading companies have certified fewer than 200 pieces with the prototype reverse.