Door County is not technically a peninsula. However, Door County has jurisdiction over much of the Door Peninsula as well as a number of islands and the water around the peninsula and islands.
Disambiguation: Door Peninsula vs. Door County
Some of the confusion over this question has to do with the difference between the Door Peninsula and Door County. While the Door Peninsula and Door County are intimately connected, these are not coterminous.
Door Peninsula
The Door Peninsula is a geological land formation that lies between Lake Michigan to the east and the bay of Green Bay to the west. This land formation is often marked on maps and charts as the “Door Peninsula.”
This land formation exists because of the durable underlying bedrock of dolomitic limestone. This bedrock is part of what’s known as the “Niagara Escarpment,” a rock formation that spans from the Door Peninsula in the west to Niagara Falls in the east.
As glaciers crept across what is now Wisconsin, lobes traveled down what is now the bay of Green Bay and Lake Michigan, carving deep gouges in the land that have since filled in with water. However, the durable dolomitic limestone of the Niagara Escarpment resisted this erosion, leaving what is now the Door Peninsula.
Door County
Door County is a political and administrative division of the State of Wisconsin. Another way of saying this is that Door County is a jurisdiction.
Door County got its name from the Door Peninsula since the majority of the land within Door County is on the Door Peninsula. However, Door County also encompasses many islands off the shore of Door County. These islands are, by definition, not part of the Door Peninsula.
Door County also has jurisdiction over the waters that surround the land of the county. If someone commits a crime in the bay of Green Bay a mile from Sister Bay, that crime might be investigated by the Door County Sheriff’s office. By definition, water is not a peninsula.
Because of these reasons, we can firmly say that Door County is not a peninsula.
What Is a Peninsula, and What Is a County?
The distinction between the Door Peninsula and Door County can become a little more clear if we understand a little bit better the difference between a peninsula and a county.
What Is A County?
In the State of Wisconsin, are political entities that serve a dual purpose. On the one hand, they are units of local government that serve general local governmental needs. On the other hand, they are also administrative arms of the State of Wisconsin. Counties in the State of Wisconsin include Milwaukee County, Brown County, and Door County. Wisconsin has 72 counties.
What Is a Peninsula?
On the other hand, a peninsula is a piece of land that is mostly surrounded by water or that projects into water. A peninsula is not a political entity. Instead, it is a geological formation.
Examples of peninsulas include not only the Door Peninsula in Wisconsin but also Cape Cod, Massachusets, the Upper Peninsula of Michigan, and the Peloponnesian Peninsula in Greece.
The majority of land in Door County is on the Door Peninsula. This is why Door County got its name. However, Door County as a political entity also has jurisdiction over water and over many islands off the shore of the Door Peninsula. This is why Door County is not technically a peninsula.
Other Counties With Jurisdiction on the Door Peninsula
Other counties also have jurisdiction over small portions of the Door Peninsula. Both Brown County and Kewaunee County have jurisdiction over southern portions of the Door Peninsula. This is another reason why Door County and the Door Peninsula are not coterminous.
Is Door County a Peninsula?
To summarize this article’s argument: Door County is not technically a peninsula, although it has jurisdiction over large parts of the Door Peninsula. The reasons why Door County is not a peninsula are:
- A peninsula is a geological feature, but a county is a political jurisdiction.
- Door County has jurisdiction over not only the Door Peninsula but also islands and water.
- Other counties have jurisdiction over parts of the Door Peninsula.
Conclusion
If you have wondered if Door County is a peninsula, this article has answered this question with a firm, unquestionable, “No.” Door County is not technically a peninsula, even though it has jurisdiction over large parts of the Door Peninsula.
Summary
- Door County is not technically a peninsula.
- Door County has jurisdiction over large parts of the Door Peninsula
- A peninsula is a geological feature.
- A county is a political entity.
- Other counties besides Door County have jurisdiction on the Door Peninsula.
