The rough isolation of Wisconsin's North Woods region is cut by part of the Gogebic range, from which much iron ore was extracted before 1965. Iron mining was resumed briefly in 1969 but has since stopped altogether. Sand and gravel, stone, and lime are other valuable mineral resources; zinc (as well as lead) is mined in the Driftless Area in the southwest. Important copper deposits were discovered in the north in the 1970s.
The state's greatest natural resource since its earliest days has been lumber. Dense forests (white pines in the north, hardwoods elsewhere) once covered all except the southern prairie. While reckless exploitation in the late 19th cent. drastically reduced the magnificent stands, extensive conservation and reforestation measures have saved the valuable lumber industry, and today c.40% of Wisconsin's land area is forested. The pulp, paper, and paper-products industrial complex in Green Bay and Appleton is one of the largest in the nation.
The state's accent, however, is chiefly pastoral. One of the nation's largest dairy herds grazes here, and Wisconsin is the leading state in the production of cheese as well as the second largest milk producer (after California). After dairy products and cattle, the state's most valuable farm commodities are corn and soybeans. Other important crops are hay, oats, potatoes, alfalfa, and a great variety of fruits and vegetables. Food processing, predictably, is one of the state's foremost industries, along with the manufacture of machinery, which is centered in Milwaukee, Madison, and Racine.
Other important manufactures are vehicles and transportation equipment, metal products, medical instruments and equipment, farm implements, and lumber. Almost all Wisconsin's major industries are to be found within metropolitan Milwaukee, where the traditional brewing and meatpacking are rivaled by the manufacture of heavy machinery and diesel and gasoline engines. Wisconsin has numerous ports on the Great Lakes capable of accommodating oceangoing vessels. The superb harbor at Superior (shared with Duluth, Minn.) has sizable shipyards and coal and ore docks that are among the nation's largest. Tourism and outdoor recreation are burgeoning, and several Native American groups operate gambling casinos in the state; through casino enterprises the Winnebago tribe has become one of the state's larger employers.