This long-term exhibition explores both the landscape and animals of the Pleistocene, or Ice Ages, of New York. Over the last two million years, New York has experienced several Ice Ages interspersed with warm periods. Gigantic glaciers covered the state, and then retreated. Each wiped the landscape nearly clean—changing the course of rivers, widening valleys, and rounding mountaintops. As a result, modern New York landscapes are geologically very young. As the last Ice Age was ending 15,000 years ago, many large mammals including mastodons, woolly mammoths, giant ground sloths, and musk oxen roamed the land. Most of these animals are now extinct or gone from New York. The exhibit features fossils of these Ice Age mammals including mammoths, caribou, moose, and whales.