From Chicago: Take I-94 to Milwaukee, I-43 to Green Bay.

Alternate routes to Door County include:
Route #1: Take Hwy 57 North from Green Bay.
Route #2: Take Hwy 310 (Two Rivers) East to Hwy 42.
Route #3: Take Hwy 42 (Two Rivers) North to Algoma.
In Algoma take County Road S North to Door County.

From Minnesota and Twin Cities:
Take I-94 to Hwy 29 (just beyond Menomonie, WI). Hwy 29 will take you to Green Bay. Take Hwy 41 north briefly and then I-43 south briefly to Hwy 57 exit going east into Door County (follow Sturgeon Bay signs).

Further directions and maps