using free USGS images there is an area of about 450 x 150 sqkm available. Location is Washington North with a basic scenery level of 9 and 11.
Currently you can find 2 airport packages, starring KOMK Omak and Whidbey Island with 4 airports at levels 12-14.
Building cultivation has been done up with Microsoft's USBuildingFootprints, with scenProc some hundred thousand trees could be planted.
Hope you like it.