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Inexplicably, township lines were entirely omitted from the TIGER import, even though TIGER has extensive township border data. That data is often quite inaccurate anyways, so it's up to us to draw the townships by hand. Note that the townships described on this page are civil townships, even though in Ohio they almost always correspond to survey townships.

Finding a township line

The first step in mapping a township boundary depends on the part of the state:

  • In counties surveyed under the Public Land Survey System, or in the Connecticut Western Reserve, aerial imagery often shows prominent roads that run through the county in a roughly 5–6 mile grid. Even where there aren't roads, you can still make out different farms along these lines.
  • In counties surveyed using the older metes and bounds method, such as in the Virginia Military District, the first step is often to identify prominent natural features that might have served as an obvious township line in the past, then go out and see whether there's a township welcome sign anywhere near there. For example, the smallest of rivers often serve as township lines because they were significant obstacles back when it took awhile to get to the nearest bridge.

Now fire up your favorite editor and switch to the USGS Topographic Maps layer. This layer displays a bunch of public domain topographic maps from the USGS laid out side-by-side. Township boundaries are generally shown as black dashed lines. They can be hard to spot, especially where they are overlaid on roads and creeks, so it helps to keep the above observations in mind.

Note that the topo layer can be slightly misaligned in places. It helps to switch back to aerial photography once in awhile, as a sanity check. If you know the general vicinity of a township line, you may also be able to spot a change in pavement quality where one township has repaved their road up to the township line.

Some editors have features that make it easy to see the topo layer at the same time you edit features on top of it. For example, if you use Potlatch 2, press D to make OSM features translucent; you can also turn on the "Show floating window" option in the Layers menu for a side-by-side display. In iD, press W to toggle wireframe mode.

Finally, you may be able to convince your county's engineer's office to let OSM copy the township lines from their official road map. But whatever the case, whenever possible, OSM prefers on-the-ground knowledge to simply copying from an existing map.

Mapping a township line

Township boundary relations are tagged with type=boundary + boundary=administrative + border_type=township + admin_level=7 + name=*. You may also specify a Wikipedia article or a website URL. See WikiProject United States/Boundaries for a comparison of admin_level=* usage in each state.

In Ohio, townships sometimes extend past county lines, for example Washington Township in Franklin County. A city or village is subordinate to its township unless it withdraws from the township by establishing a coextensive paper township. (If the municipality then expands into an additional county, a separate paper township is sometimes established.)

Do not map paper townships. Boundary relations should exclude the paper townships of municipalities that have withdrawn. In other words, the township starts at the welcome sign, not necessarily where the township was historically. In cases where a withdrawn municipality has annexed some land but its paper township's boundaries have not been updated – it happens sometimes – the adjacent real township should overlap the municipality. If the paper township's name does not match its municipality's name, tag the municipality's relation with the paper township's name in alt_name=*.

Many roads are built along township lines, and township lines can also follow rivers or other natural features. If the township boundary is legally defined as the feature, then they should be welded together.[a] Please do not make the feature itself a member of the boundary relations. However, if the boundary is not legally defined as the feature, or if a road section doesn't literally straddle the boundary (with either side named and maintained differently etc.), then they should be mapped separately, as the feature might not be exactly aligned with the legal boundary (and could become further misaligned in the future).

At the center of some townships lies a population center of the same name. The GNIS import introduced place=town POIs to represent these population centers. Each POI represents a settlement with an indefinite boundary, rather than the administrative unit represented by the boundary relation, so the name=* tag should not contain the word "Township".


Status of township mapping by county.

As of 2023, most of the progress has been in central, north-central, and southwestern Ohio. Use this Overpass turbo query to find correctly tagged townships.

County code County name Total townships Townships mapped Notes
ADA Adams 14 0
ALL Allen 12 5 Auglaize, Jackson, Monroe, Bath, and Richland Townships are completed.
ASD Ashland 15 15
ATB Ashtabula 27 5 Colebrook, Orwell, Wayne, Williamsfield, and Windsor Twps are completed.
ATH Athens 0
AUG Auglaize 0
BEL Belmont 0
BRO Brown 0
BUT Butler 13 13
CAR Carroll 14 14
CHP Champaign 12 0
CLA Clark 0
CLE Clermont 14 14
CLI Clinton 0
COL Columbiana 0
COS Coshocton 22 22
CRA Crawford 16 16
CUY Cuyahoga 2 2
DAR Darke 0
DEF Defiance 12 12
DEL Delaware 18 18
ERI Erie 9 9
FAI Fairfield 0
FAY Fayette 0
FRA Franklin 17 17
FUL Fulton 0
GAL Gallia 15 15
GEA Geauga 16 16 Incorrectly tagged; also excludes CDPs from townships
GRE Greene 0
GUE Guernsey 0
HAM Hamilton 12 12
HAN Hancock 0
HAR Hardin 15
HAS Harrison 0
HEN Henry 13 13
HIG Highland 0
HOC Hocking 0
HOL Holmes 0
HUR Huron 19 19
JAC Jackson 0
JEF Jefferson 0
KNO Knox 22 22
LAK Lake 0
LAW Lawrence 14 14
LIC Licking 25 25
LOG Logan 17 17
LOR Lorain 18 18
LUC Lucas 0
MAD Madison 14
MAH Mahoning 0
MAR Marion 15 15
MED Medina 17 17
MEG Meigs 0
MER Mercer 0
MIA Miami 0
MOE Monroe 18 18
MOT Montgomery 0
MRG Morgan 0
MRW Morrow 16 16
MUS Muskingum 0
NOB Noble 0
OTT Ottawa 12 12
PAU Paulding 0
PER Perry 0
PIC Pickaway 15 15
PIK Pike 14 0
POR Portage 14 14
PRE Preble 0
PUT Putnam 15 15 Need tagging improvements (some names might be wrong + add Wikipedia).
RIC Richland 18 18
ROS Ross 0
SAN Sandusky 0
SEN Seneca 15 15
SCI Scioto 0
SHE Shelby 0
STA Stark 17 7
SUM Summit 9 9
TRU Trumbull 25 25
TUS Tuscarawas 0
UNI Union 14 14
VAN Van Wert 0
VIN Vinton 12 8
WAR Warren 0
WAS Washington 0
WAY Wayne 16 5 Completed Congress Twp., Plain Twp., Paint Twp., Clinton Twp., and Chester Twp.
WIL Williams 12 12 Montpelier needs to be clipped.
WOO Wood 0
WYA Wyandot 13 13
  1. For example, in Butler County, the border between Liberty and West Chester townships follows Hamilton-Mason Road. There is a way way that belongs to the relation Liberty Township and relation West Chester Township boundary relations. (In the event this border is also a city or county border, the way can belong to those relations as well.) This boundary way is joined to way Hamilton-Mason Road at every node along the road. (In Potlatch, press F repeatedly to "follow" the road you're welding the boundary to.)