[Talk-us] National Forest boundaries

[stevea]

On Jun 26, 2020, at 7:31 AM, Bradley White <theangrytomato at gmail.com> wrote:
> In most county assessor records, the name on the "title" of USFS owned
> land is "United States of America", "United States Forest Service", or
> some variant. The federal government owns the land, and manages the
> land resource as well as US citizens' legal right to access the land
> (barring conservation necessities that limit access to certain users
> or any public at all).

We can chalk up "owned by USFS" is really "operated by USFS and owned by the People" as a minor quibble, we're saying the same thing.  Yes, sometimes "conservation necessities" means on certain polygons, protect_class=6 and / or access=* might be changed to other values.  Makes sense.

>> A USFS NF is a "virtual" multipolygon (not one in OSM, we get to that later) of three kinds of things:
>> 
>> 1) An "outer" (but not the largest one) which is "the enclosing land which USFS manages, except for inholdings, below,"
>> 2) Zero to many "inner" polygons, representing inholdings (and with the usual "hole" semantic of exclusion from 1), above and
>> 3) An even LARGER and ENCLOSING of 1) "outer" which Congress declares is the geographic extent to which USFS may or might "have influence to someday manage."
> 
> Sort of. Administratively, the USFS operates 9 regions containing 154
> "national forests", with each forest being subdivided by a number of
> ranger districts. The federal government also owns large swaths of
> land across the country. These parcels are then managed by whichever
> national forest (and ranger district) they happen to be located in.
> There isn't necessarily an "outer" way enclosing the land that the
> USFS manages, there is just a sum of US-owned parcels that fall within
> a certain NF boundary that represents the actual land managed by the
> USFS. In OSM practice, this is often a very complicated multipolygon
> with multiple 'outer' members, which is usually required in order to
> avoid self-intersecting rings.

One clear take-away from this is self-intersecting rings are not OK.  OSM's rules for a proper multipolygon say that already, so no harm, but OK, at least Congress and OSM's rules for "don't self-intersect in multipolygons" agree with each other.  (Good).  A more significant result I get is that the "big outer" isn't "enclosing" but rather a "sum."  That makes sense, too:  these shouldn't necessarily be contiguous and I'm sure in many cases they are not.  So I now understand that was a minor fault in my 1) 2) 3) posit (1, specifically).  However, where I fail to "tame the tiger I've grabbed by the tail" is how that sum (of outers) "falls within a certain NF boundary that represents the actual land managed by the USFS."  I read those words over and over again and still am confused between what they say and how I've posited 1) (a bit better now) and 3).  Why do we need both?  Do we?  I guess I'm still fuzzy on that pesky "Congressionally-defined" boundary separate from the logical "sum" of the outers which are USFS-managed.  Does an OSM multipolygon need to delineate this ("falls within..."), or is it sufficient that "the sum of US-owned parcels" (as outers, with inners logically subtracted) already fully describes the multipolygon?  Please help me understand why Congress declares something that "the logical geometry" (of a proper multipolygon) already describes!

I appreciate Paul's interjection of "here is some mind-blowing mess," as I think most of us who look at such geo data / landuse / land ownership / management and have seen such "checkerboards" understand this sort of micro-level of complexity as "merely" a pattern of more-or-less regularized (square mile at-a-time) application of these macro-level rules we're hammering out.  I'm fine with properly tagging BLM, USFS, BLM, USFS, BLM, USFS on miles inside of township-sized grids inside of a federally-managed area.  I'm not (quite, yet) fine with the higher-level "whole thing" tagging which includes that pesky Congressionally-declared entity.  I and we get closer, I think, as Bradley's "Sort of" exposition gets ME closer, but (and I don't want to seem like I'm simply drubbing this horribly) I don't think we (readers of this list) are fully there yet.

It DOES seem that OSM can well-construct USFS NF multipolygons with one-to-many outers, one-to-many inners (inholdings) and both tags on the multipolygon itself (protect_class=6, operator=USFS, protection_title=National Forest...) AND tags on the individual inner members which are different (operator=BLM, for example).  I've understood this and tagged like this for many years (and thought I've done a decent job of building NFs, at least in California, where I primarily map).  But then this topic of Congressionally-defined reared its head, and it still spins mine around.  Can anyone continue to offer more clarity about this?  Bradley, thank you so much for all you've said so far, I do get closer and I hope the list does as well.

SteveA