Tools made about 11,000 years ago were found at the Maple Avenue site of Keene’s new middle school, which Stoddard archaeologist Robert Goodby said could “easily be one of the most important (archaeological) sites in the state, if not New England.

Goodby began his site review, overseen by the N.H. Division of Historical Resources, in November. The review is a federal requirement for projects that are constructed near wetlands. In addition to the high number of artifacts, few Granite State sites hold older finds, except one in Swanzey where 11,600-year-old stone tools were found....