Switzerland in the Roman era after which the area began to be occupied by Germanic peoples. The Swiss plateau, within the natural borders of the Alps to the South and East, Lake Geneva and the Rhône to the west and the Rhine to the north, was recognized as a contiguous territory by Julius Caesar. This area had been dominated by the La Tène culture since the 5th century BC, settled by a mostly Celtic population (Gauls), of which the Helvetii were the most numerous, but which also included the Rauraci in north-west Switzerland centered on Basel, and the Allobroges around Geneva. South of the Swiss
Zumbro River The South Fork Zumbro River, long, rises about east of Hayfield in southern Dodge County and flows generally eastwardly into Olmsted County, where it turns northward at Rochester and flows into southwestern Wabasha County. The South Fork's course through Rochester has been channelized as part of a flood control project. It is dammed in Wabasha County, by the Lake Zumbro Hydroelectric Generating Plant to form Lake Zumbro. The Middle Fork Zumbro River, long, rises in northeastern Steele County, about west of West Concord and flows generally eastwardly through northern Dodge, southwestern Goodhue and northeastern Olmsted counties, past Pine Island and