Plant and animal fossils go way back in Fall River County — 100 million years back. When the John Jacob Astor expedition arrived in 1811, one of the men reported seeing “a forest of solid stone” at the headwaters of the Cheyenne, southwest of today’s Hot Springs. Sadly, many of the surface fossils have been carried away but in 1974 workers were digging a home foundation on the edge of town when they found a mammoth tooth. It seems that 20,000 years ago the site was a drinking pond for wooly and Columbian mammoths. Over time, dozens of beasts fell into the mud and couldn’t climb up the slippery slope. The active dig, now known as the Mammoth Site, continues today beneath a big roof and the watchful eyes of scientists from around the globe and interested travelers and tourists. It’s an amazing stop for children and anyone with a sense of curiosity.