Near the center of Nebraska's tall-grass prairie, on the eastern edge of hunting grounds once used by the Pawnee Indians, the Pawnee, Nebraska's largest tribe, located villages on major streams including the Blue, Loup, and Platte Rivers. Beginning in the 1840's, wagon trains from Nebraska City on the Missouri River to frontier settlements and military posts farther west carried people and goods through the area, and the freighters' trail known as the Nebraska City-Fort Kearny Cutoff ran a few miles south. Frontier settlement began in the 1860's, Seward County was organized in 1865, and the countryside was rapidly colonized during the following decade. This fertile watershed of the Big Blue River attracted many German immigrants, including some by way Russia, as well as Scandinavians. Through the use of deep-well irrigation, the region was developed in recent decades into a major center of successful, intensive farming, and westward the tall-grass prairie gradually merges into the short-grass country of the semi-arid plains.