After getting back into the workflow of scenery creation I decided to document this "simple" process so I don't forget again.
Download the raster image of from the USGS.
Using QGIS
Layer/Add Raster Layer
Raster/Conversion/Polygonize (Raster to Vector)
After the above step you have one big vector file (shape) that can be subdivided into many by the DN value.
Vector/Data Management Tools/Split vector layers
Finish by renaming and selecting colors to represent the land class. Add in stream, road and rail layers and you end up with this.
All the data in this project came from the same USGS site. I think it will prove to be superior to the custom scenery available in my sig which was made up of "rounded" NLCD and other hydro and deciduous sources plus OSM road and rail.
Time will tell as I plan to run this in the next week to see how it looks and more importantly how it behaves in FG.
The above work was completed in a few hours (half of that was waiting for processes to complete). If I remembered correctly i should be able to generate the entire state of KS in less than 24 hrs.