Michigan, where I lived the longest, is two different peninsulas jutting into the Great Lakes system. Until they were connected by a long bridge in 1957 (120 years after statehood) the only land route to a portion of the state involved crossing through what is now three different states. The Upper and Lower Peninsulas are pretty easy to understand names, though. A visitor hearing “da UP” might be a little more confused. The lower peninsula is shaped like a right hand. It’s sometimes referred to as the Mitten.
The northern lower peninsula is much hillier thanks to the glaciers that carved the Great Lakes. While not a geographical name I’ve known people in that area that referred to those of us down south as flatlanders. Likewise, I’ve heard reference to those living in the LP as trolls; we lived under the Mackinac Bridge.
The Detroit River starts in the Detroit and runs south to empty into Lake Erie. The communities further along the river from Detroit are frequently referred to as collectively as Downriver or the Downrivers. It’s not an inventive name but it can confuse people not from the area.
Lake effect snow zones get referenced in weather reports. Storms moving across the Great Lakes can have the air warm quite a bit and get saturated with extra moisture from the exposed water. That can make them primed and ready for an extra heavy snow fall once the make landfall. People who live there tend to know …or learn fast.