About 15,000 years ago, huge glaciers covered this area and formed unique geological features throughout the valley called drumlins, hills of glacial till deposited beneath the ice, while periodic ice dams on the Kootenai River created a vast inland lake. For centuries, the Kutenai Indians lived here and grew a form of tobacco on the plains near the river, giving the area its name. Trade in the region was first dominated by Canadian fur companies, and in 1808 North West Company trader and geographer David Thompson first explored the Kootenai River. For decades, the company conducted lively trade with the Kutenai, Salish, and other tribes of the inland Northwest. Rich gold strikes on Wild Horse Creek in southeastern British Columbia brought American prospectors in the mid-1860s, and although gold did not reward many of them, their reports of abundant resources attracted miners, cattlemen, farmers, and loggers to northwestern Montana. In the 1890s, steamboats traveled the river carrying mail and supplies to people living north of Jennings, before the Great Northern Railway replaced them in 1901.