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Massachusetts Conservation Land and Trails Mapping Guidelines

This page reflects rough consensus from the talk-us-massachusetts list, the gathering place of active mappers in Massachusetts. Significant edits should be discussed there.

Conservation Land (the areas themselves)

Determining and understanding boundaries

Many of the conservation properties in OSM were bulk imported from MassGIS Data: Protected and Recreational OpenSpace dataset in 2009. The original data layer was created by tracing from locally contributed paper maps (1988-1998), therefore its boundaries have tens of meters of position errors.

The MassGIS L3 Parcel layer is a good source for the property boundaries. This layer is available from MassGIS as a web service and is available in JOSM and Vespucci via the imagery menu. Beware that conservation status may be sub-parcel (conservation restrictions in particular). Beware that while L3 Parcels is pretty good, mappers may have drawn boundaries on the map more accurately, e.g. by reading deeds and looking at stone walls. Therefore, be careful if something seems close in a way that indicates an L3 error, vs simply a very inaccurate parcel layout probably from the import. When in doubt, ask the local mappers who edit conservation land in that town.


  • If the primary purpose of the land is conservation, meaning preserving the land in a natural state for the indefinite future, Tag:landuse=conservation. This is not rendered in the default style, but it is rendered in OsmAnd, and of course people making their own renders can use it. This tag is appropriate for land with conservation restrictions as well as conservation land owned by a government or land trust.
  • If the landowner harvests trees as the primary use (like NEFF), Tag:landuse=forest (rendered). Note that being called "Town Forest" does not imply that forestry is the current primary use, and typically it is not.
  • Tag:landuse=reservoir_watershed is in use for land whose purpose is to protect water supplies. (There is some disagreement about this.)
  • If the land is legally permanently protected against use inconsistent with conservation, use Tag:boundary=protected_area. Examples are government land formally in conservation status, and land with a Conservation Restriction (most land trust land has a CR). Note that some land may be currently used as conservation (e.g. town-owned land maintained in a natural state) but not have legal protection, meaning the town could decide to e.g. clear it and build a school. And, forestry land can be protected, as forestry is typically not disallowed on land with a CR. It is thus important to understand that Tag:boundary=protected_area and Tag:landuse=conservation do not mean the same thing, even though both are applicable to many parcels.
  • If the land (conservation, forestry, reservoir protection, whatever) is open to the public for hiking, use Tag:leisure=nature_reserve. If the land is not open to the public for hiking (like a conservation restriction on a private farm, some forestry areas), don't add a leisure tag. Opinions are likely split whether large CRs should be mapped as Tag:landuse=conservation or left unmapped. Note that accees tagging is particularly important for CRs not open to the public, or indeed any mapped feature not open to the public.
  • Use Tag:access=yes to state that the public may go on the land, and Tag:access=private to state that they may not.
  • Realize that a CR not open in general to the public may have a trail that is open to the public, via a trail-specific easement. This means the area is tagged private but the trail is tagged for access.
  • Use Key:owner for the person or organization that owns the land.
  • Use Key:website if the property owner has an official web page describing the property.
  • Consider Tag:leisure=recreation_ground for athletic fields and Tag:leisure=park for urban-style (non-wild) parks.

Trails (the paths along which you can hike)

  • Use Tag:highway=path for a trail that is not passable by a 4WD vehicle.
  • Use Tag:highway=track if the trail is physically passable by 4WD vehicles. If so, set Key:motor_vehicle to private or emergency if the public is not allowed to drive on it. (This is fairly common for major trails in some conservation areas, especially those used for logging in the past.)
  • If there is a notion that the trail is particularly appropriate for travel on foot (vs bicycle or horse) or a notion that the trail is primarily for foot users, add Tag:foot=designated. This is typical for most conservation area trails. Clues are notions that other users should yield to foot traffic, other modes not being allowed, and other modes having any sort of restriction (e.g., dry ground only, or some trails not allowed on the property to bikes, but all by foot).
  • Note that there is an alternate Tag:highway=footway for a path where hiking is the primary use. This is technically equivalent to Tag:highway=path and Tag:foot=designated and is generally treated the same way. Some, probably more MA mappers than not, prefer to use path for trails, and footway for more urban/paved/manicured walkways, even though renderers can not reliably make this distinction. Overall, almost everyone believes one of "use path for trails in the woods" or "use path or footway; doesn't matter", and therefore having a norm of "use path" does not cause problems.
  • Key:access - Use Tag:access=yes or if the trail is known to be open to the public by law (easement (perhaps on a CR), owned by the town, etc.) or if there is a strong notion that anyone may use it (perhaps only during daylight), such as a land trust that says the public may visit. Use Tag:access=private if the trail is on private property, and it is known that the land owner doesn't want people on it, or if the trail is on residential property or some other situation where that is the default assumption. Use Tag:access=permissive if it is well known that the land owner does not mind the public being on the trail, but they can change their mind at any time (use this tag with caution, and typically only if you are really local). Do not add an access tag, if you aren't sure if it is OK to be on the trail or not. Err on the side of caution by not adding an access tag.
  • Think carefully about whether a trail should even be mapped, especially if it is on residential property and you haven't spoken to the owners.
  • Use Tag:surface=paved, Tag:surface=ground, or some more specific value. Try to avoid Tag:surface=unpaved as vague.
  • Use Key:width to denote the width of the trail. Perhaps round to 0.5, 1 and 2m, or numbers that are equally round, if that is reasonable.
  • If the trail has a name, use Key:name to store it. It is common practice to tag a trail with red blazes as Key:name =Red, even though strictly speaking this is not a name. The Key:name should not be used as a description.
  • Use Key:operator to name an organization (e.g., government) if the trail is formally maintained, such as by a town conservation commission, or a land trust.
  • Use Key:colour to record the color of the blazes marking the trail. See also name, and note that how to record blaze information is a work in progress.