The Big Bend of the Platte River in central Nebraska is one of the most important staging areas for the spring migration of the world's largest population of sandhill cranes. Throughout history the Platte has also been a corridor of migration for native peoples and Euro-americans. For both cranes and humans, the river has provided water, food, and shelter in a sometimes harsh environment. No one knows when sandhill cranes appeared on the Nebraska landscape. Their remains have been found in nine-million-year-old deposits in western Nebraska and in prehistoric and historic Native American sites throughout the central plains. The journals of explorers and fur traders such as Edwin James (1820), John Townsend (1834), Rufus Sage (1841), and John J. Audubon (1843) mention sandhill cranes they observed while traveling up the Missouri River or along the Platte. Settlement of the Great Plains brought many changes to the Platte. Irrigation reduced its volume, and its shorelines and islands became overgrown when prairie fires and floods were controlled. Only the Big Bend region still provides prime habitat to sustain the annual migration of sandhill cranes.