Here is a list of Township with County Lettered Highways that are open (unless marked otherwise).
Adams (most lettered Highways and all township Roads)
Albany (all lettered Highway sand all township Roads)
Clarno (all township Roads)
Cadiz (all lettered Highways and all township Roads)
Decatur (all lettered Highways and all township Roads)
Exeter (all Lettered Highways and all township Roads)
Jefferson (limited letter Highways and all township Roads)
Monroe (Limited letter Highways and all Township Roads)
Mt Pleasant (all lettered Highways and all Township Roads)
Spring Grove (limited lettered HighwayRoutes and all township Roads)
Sylvester (all lettered Highways)
Washington (all lettered Highways and all township roads)