Where is Badenburg?

The exact location of the fictional walled city of Badenburg is unclear. So where is it? I need to know to write my second story for submission to the Grantville Gazette. But there are clues scattered in the books and the Gazette. Here are some images I used in my research. They were derived from a copy of the map by Mike Bartholomy and many barflies showing the part of the city of Grantville superimposed on terrain maps from modern Germany.

Here I’ve cropped it and added more text plus a circle of where the Ring appeared. Click it to see a larger higher-resolution image.

Here is a closeup of where Grantville’s Hwy 250 dead ends. It is near our real time Germany Hwy 88. Click the image to see a larger version.

Here is Badenburg’s location. Click the image to see a larger version.