Darke County has at least 2 maps that show the government survey section, township and range lines as well as the boundary lines of the political townships and municipalities: one is issued by the Darke County EngineeringOffice and the other by the Greenville Chamber of Commerce. At least they were in 1996 when I last visited there. I would suggest that you check with the County Engineering Dept. and the Chamber of Commerce in Dayton to see what they have. Rembember of course that the political township boundaries are not idetical to the government survey boundaries and that they have been contracted or expanded over the years. New political townsips have also been created from time to time and some have ceased to exist (e.g. Madison & Randolph twps. in Montgomery County) when all of their land became included within municipal limits.