09/11/2026
Camp Cobus Where "Up North" Begins!🌲⛺️
The Canadian Shield reaches down into Wisconsin's northern counties, and that ancient rock explains why the Northwoods look and feel completely different from the rest of the state.
The Shield is the exposed core of the North American continent, some of the oldest rock on Earth. In Wisconsin it surfaces across the north, roughly from the Bayfield Peninsula east through Iron, Vilas, Oneida, Forest and Florence counties, with outcrops appearing farther south in the Wolf River area and the Baraboo Hills.
The rock runs Precambrian, much of it between one and three billion years old. Granite, gneiss, basalt, quartzite and greenstone. The Penokee Range in Iron and Ashland counties is banded iron formation, which is why mining was proposed there and why that became a major political fight in the 2010s.
What that geology does to the landscape is the important part. Shield rock is hard and does not weather into deep soil. Glaciers scraped across it repeatedly and left only a thin cover of till, sand and gravel. So northern Wisconsin has poor, acidic, sandy soil.
That is why the north was never good farm country and why it stayed forested. Loggers took the white pine in the 1800s, settlers tried to farm the cutover land, and most of them failed. The land went back to forest, and the counties eventually became the timber, tourism and cabin economy they are now.
The same rock created the lakes. Glacial ice gouged basins into it and left thousands of them, which is why Vilas County alone has around 1,300.
South of that line, in the driftless and the till plains, the bedrock is younger sedimentary rock covered by deep glacial soil, and that is where the farms are.
One rock boundary, two Wisconsins.
