Lake Winnebago, Winnebago County. Winter, date unknown. Altitude c. 150 ft. Three fishing shanties, several vehicles, and several fishermen are seen on the sunny, frozen surface of northern Lake Winnebago, Wisconsin's largest inland lake. Gray patches of wind-swept,snow-free ice interrupt its otherwise white veneer. Perch, walleyed pike, and sturgeon (taken only during a special spearing season) are the most sought-after species in winter.