The Chelan area was home to Salish speaking Native Americans known as the Chelan tribe prior to white settlement in the late 1800s. But before the settlers arrived, a new beast, the horse, came and with it just as quickly were smallpox, measles and other deadly infectious diseases. These diseases wiped out an estimated 90% of the Indians before David Thompson, the very first explorer in the area, arrived on the Columbia in 1811. The horse and the culture of the horse so prevalent with Indians of the Plains also took over by the time explorers and settlers arrived, so it is difficult to know what the original inhabitants' lives were truly like and who the Indians were before these monumental changes to their way of life. A people of the horse, though, they quickly became, adopting Plains Indian dress, beadwork, and more, and with white settlers came far more changes.