I have a map that is using DDP to index through and show ~1800 short line features (bridges), and I need the map to be pretty zoomed in because I'm wanting to show the immediate context (especially local road names) of where the bridge is. While this is easy enough to do, in this application, I think it is important to give the broader context of the location. These bridges cover a 21 county area, and I want to have an inset map that shows the current county with an extent indicator that shows where in the county the current extent is showing. I realize that I could do this by having a separate map document for each county, but that feels like it would kind of defeat the purpose of DDP.
From what I've found researching this issue, it isn't possible to have multiple indexes, which is what I would want. Is there a way in python to make the inset map "zoom to feature" based on the county name that is listed for the current feature in the index?