In the early 1990s, second-graders in Mrs. Sara Jane Aebly's class at Windsor Elementary School discovered that Washington State did not have an official state fossil. Encouraged by their teacher, they decided to try to create one.
After some research and discussion, the students settled on Mammuthus columbi, the Columbian mammoth. Until about 12,000 years ago, Columbian mammoths populated much of North America, from present-day Canada to as far south as Nicaragua. These relatives of the elephant could be about 12 feet tall and weighed 7–9 metric tons. Many of the best specimens have been discovered in Eastern Washington, where the repeated Ice Age Floods left "a giant bathtub ring" of mammoth skeletons.
The effort to win official approval of the Columbian mammoth as Washington's official fossil took years, carried on by a series of students in Aebly's classes. In 1998 four Cheney students went to Olympia to testify before the state legislature. The bill to make the Columbian mammoth the official state fossil was passed and signed into law by Governor Gary Locke that same year.