More on Germantown

...
Germantown, Indiana
Germantown, Indiana, was founded in 1834 in what is now Geist Reservoir. It was actually built on the old north bank of the old Fall Creek. Residents, primarily of German heritage, from nearby Oaklandon founded the town following a disagreement over the murder of an Algonquin in Oaklandon. With just one general store, a shoemaker, a one-room schoolhouse and a mill, Germantown was very small. The town had about 20 residential properties in total.

The Start of Geist Reservoir
In the 1900s, water deficits in the Indianapolis area appeared to be impending issue. One man, Clarence Geist, a former owner of the Indianapolis Water Company, drew up plans for the creation of Geist Reservoir. The plan called for the damming of Fall Creek, which would, consequentially, flood the small town of Germantown. The obvious fate of the town did not stop the damming of Fall Creek. In 1943, the creek was dammed and began to flood the surrounding area, creating Geist Reservoir. Most of old Germantown no longer exists today. However, nearby Log Cabin Animal Hospital now occupies the oldest remaining Germantown structure.
...

Excerpt from:
FindingHomesIndy.com's "Geist Reservior" by Lisa Witsken-Gearhart