HOT SPRINGS, S.D. (AP) — Construction is underway on an expanded learning center at the Mammoth Site in southwestern South Dakota.

The world-renowned site has been under exploration since 1974, when a construction crew dug up mammoth bones on the south side of Hot Springs. At least 60 mammoths have been found in the area.

Ground was broken Wednesday for the 5,800-square-foot center addition. It will feature a new entryway, gathering area, storage and two 53-seat theaters. The project will cost nearly $1.4 million, with help from the federal government.

About 100,000 people visit the site each year.

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