both of these tripoints are still believed to be virgins
& as topozone indicates
neither is believed to be marked
except perhaps as speculated by brian in message 6846
note however that bus&ss states there are only the 177 idwa
markers in the series shown on the topos
so we cant presume there is a forgotten number 178 anywhere
let alone at bcidwa
on the other hand
the idea of a forgotten bcidmt marker in the form of a hypothetical
idmt marker number 1 is slightly more plausible
in any case i think you are right to prepare for 2 unmarked points
& you can always be pleasantly surprised if you do find
something at the supposed locations
the abcde classifications of relative success mentioned by mike
have been generally used
but for unmarked points
there is no objective standard or standard objective
other than the best available truth
& because every situation is unique
you can only do the best you can do in each case
to create the level of objective accuracy you desire & believe
possible
& indeed
tho i havent unzipped or checked or grasped all your data
i myself am leery of introducing possibly spurious levels of
accuracy
& i think brian may have been right to hold the line at integral
degminsecs of lat & long
because that is about all one can get from careful
measurements of the paper copies of the usgs topos
given their limitations
& i think these may actually be the best available data
in both of the present cases
notwithstanding all the published ibc marker coords
& then
having done that
your best shot may well be simply visiting the geocoords
indicated by the topos
with the help of your gps receiver
however
since caus is marked by intervisible monuments on the clearcut
you ought to be able to improve on your gps reading
whatever its level of accuracy
by eyeballing & aligning yourself with the nearest caus markers
then you will have perhaps a 100 foot length of caus on which to
pace back & forth in each case
& guess the locations of your targeted tripoints
for it appears the far greater challenge will be to align with the
state lines converging upon caus from the south
since their terminal marker pairs are almost certainly out of view
from caus
& even if you could sight to or from them
you would still have the problem in both cases of projecting the
final segments of the state lines from these pairs of terminal
markers
idmt 3 & 2 on the one hand
& idwa 176 & 177 on the other
for the projections are only presumptively due north lines
whereas technically they run from marker to marker
& should actually run slightly askew
having been surveyed & marked about a century ago
when standards of accuracy werent so high as they are now
of course if you could just find these last 2 markers in each case
& take gps readings of their actual latitudes & longitudes
& then project the state lines thru them as far as the caus sight
line
& then find these projected points by gps readings on the caus
sight line
no one might ever be able to improve on that methodology
but thats a lot of work or play
in any case
best wishes for success
however you define & do it
as these are certainly a couple of very challenging points
--- In
BoundaryPoint@yahoogroups.com, "Dave Patton [DCP]"
<dpatton@c...> wrote:
> The short version of this email:
> ----------------------------------------------------------
> - has anyone visited BCIDWA or BCIDMT, and if so,
> is the visit info online?
> - if there have been no visits, is there info online
> that documents the locations of these tripoints?
> - for the Degree Confluence Project we have rules about
> what constitutes a successful visit to a confluence,
> and that is all outlined on our website - is there
> somewhere that I can refer to online for this group's
> 'rules' for a successful tripoint visit & documentation?
> ----------------------------------------------------------
> The long version is listed below :-)
>
>
> Two years ago, I asked in this group for any information
> about the British Columbia/Idaho/Washington(BCIDWA) and
> British Columbia/Idaho/Montana(BCIDMT) tri-points:
> http://groups.yahoo.com/group/BoundaryPoint/message/6843
>
> I never did make it to either point - my trip was cut short:
>
http://www.confluence.org/confluence.php?lat=49&lon=-117&visi
t=2
>
> I may be going to the area of these tripoints again fairly soon.
> Brian Butler indicated in 2002 that he was going to try visiting
> these tripoints in 2003:
> http://groups.yahoo.com/group/BoundaryPoint/message/6846
> but his website doesn't have any info about them:
> http://www.bjbsoftware.com/corners/us_canada.html
> and he hasn't replied to a recent email(June 30th) from me.
>
> Does anyone have any additional information?
>
> Here's what I have so far. I'm using OziExplorer as
> my mapping program. Unless otherwise indicated, all
> coordinates listed below are using NAD27 CONUS.
>
> BCIDWA
>
==================================================
====================
> A) Data sources
> From the University of Washington Geospatial Data Archive
website:
> http://wagda.lib.washington.edu/data/drgs.html
> the Salmo Mountain 1:24,000 DRG(with full map collar):
>
http://duff.geology.washington.edu/data/raster/drg/sandpoint/o48
117h1.zip
>
> From the Idaho Panhandle National Forests GIS webpage:
> http://www.fs.fed.us/ipnf/eco/yourforest/gis/index.html
> the IPNF National Forest Boundary in Arc/Info export
format(e00):
> http://www.fs.fed.us/ipnf/eco/yourforest/gis/lands/forestbdry.zip
> NOTE: the e00 file was imported into OziExplorer as a track,
> assuming NAD27 CONUS, and UTM Zone 11.
>
> International Boundary Commission's NAD27 Boundary
Segments webpage:
>
http://www.internationalboundarycommission.org/ibccoordnad27
.htm
> the data for section M. 49th Parallel:
>
http://www.internationalboundarycommission.org/coordinates/M
49thp.txt
> NOTE: the NAD27 IBC data was converted to a format that
could be
> imported into OziExplorer as a waypoint for each boundary
monument.
> NAD27 was assumed to mean NAD27 CONUS.
>
> B) Data validation
> DRG map image is calibrated correctly, as UTM and lat/lon
> grid lines superimposed by Ozi match up with the map's tick
> marks. Map image calibration done automatically by
OziExplorer.
>
> The locations of the Canada/USA Border Monuments 194 and
195
> are shown on the DRG, and the waypoints from the IBC data
are
> shown on the map as matching the center of the map symbol.
>
> The track showing the IPNF Boundary matches closely with the
> Canada/USA and Washington/Idaho borders.
>
> C) BCIDWA Tripoint Coordinates
> Based on setting a waypoint in OziExplorer, centered on the
> junction of the Canada/USA border with the Washington/Idaho
> border, as shown on the DRG:
> N 48° 59' 57.3628" W 117° 01' 52.7731"
> From a June 2002 email from Brian Butler:
> N 48° 59' 57" W 117° 01' 53"
> From the "corner" trackpoint of the IPNF Boundary data:
> N 48° 59' 57.4096" W 117° 01' 53.1115"
>
> If there is a monument at the Cananda/USA border, then it
> of course would be definitive as to the tripoint location.
> The DRG to the south of Salmo Mountain, Helmer Mountain:
>
http://duff.geology.washington.edu/data/raster/drg/sandpoint/o48
117g1.zip
> shows Washington/Idaho Border monuments 165 and 166,
with 166
> being to the north of 165. The Salmo Mountain DRG shows
monument
> 177, which is 949 meters due south of the border.
>
> If there is no Washington/Idaho border monument at the
Canada/USA
> border, I'm inclined to consider the first coordinate shown
above
> to be the best one at this point, because:
> - Brian's coordinates are only to the nearest second, and don't
> place the waypoint exactly on the border intersection
> - the IPNF boundary data matches the middle of the
Cananda/USA
> border line shown on the DRG, and also matches the middle
of the
> Washington/Idaho border line shown on the DRG south of
border
> monument 177. However, there is a data point at monument
177,
> but north of that, the next two data points(one of which is the
> "corner" point)line up with the west edge of the
Washington/Idaho
> border line, not the center.
>
==================================================
====================
>
>
> BCIDMT
>
==================================================
====================
> A) Data sources
> From the Idaho Department of Lands Geographic Information
Systems
> http://gis.idl.state.id.us/GIShtm/static/GisProgram.htm
> via the Dynamic Data Server, the Canuck Peak 1:24,000 DRG
> (with full map collar):
> http://gis.idl.state.id.us/webGIS/drgzip/h1rc4816.zip
>
> International Boundary Commission's NAD27 Boundary
Segments webpage:
>
http://www.internationalboundarycommission.org/ibccoordnad27
.htm
> the data for section M. 49th Parallel:
>
http://www.internationalboundarycommission.org/coordinates/M
49thp.txt
> NOTE: the NAD27 IBC data was converted to a format that
could be
> imported into OziExplorer as a waypoint for each boundary
monument.
> NAD27 was assumed to mean NAD27 CONUS.
>
> From the Idaho Panhandle National Forests GIS webpage:
> http://www.fs.fed.us/ipnf/eco/yourforest/gis/index.html
> the IPNF National Forest Boundary in Arc/Info export
format(e00):
> http://www.fs.fed.us/ipnf/eco/yourforest/gis/lands/forestbdry.zip
> NOTE: the e00 file was imported into OziExplorer as a track,
> assuming NAD27 CONUS, and UTM Zone 11.
>
> B) Data validation
> The Canuck Peak(h1rc4816) DRG map image, when
automatically
> imported into OziExplorer doesn't appear to be calibrated
> correctly. UTM and lat/lon grid lines superimposed by Ozi
> match up with the map's tick marks for Longitude, but are
> "not quite right" for Latitude. Also, the IBC border monument
> waypoints show up slightly north of the symbols on the map,
> and the IPNF boundary tracklog shows up as slightly north
> of where it should be(e.g. in the vicinity of Canuck Peak).
>
> I used OziExplorer's 'Move Map Calibration' tool to adjust
> the map calibration by 6 pixels, and then all the grid lines
> matched the map ticks.
>
> The locations of the Canada/USA Border Monuments 220, 221,
> and 222 are shown on the DRG, and the waypoints from the
> IBC data are shown on the map as matching the center of the
> map symbol.
>
> The track showing the IPNF Boundary matches the NAD27
49th
> parallel, and also the boundary line drawn on the DRG in
> the lower part of the quadrangle, near Canuck Peak.
>
> C) BCIDMT Tripoint Coordinates
> Based on setting a waypoint in OziExplorer, centered on the
> junction of the Canada/USA border with the Idaho/Montana
> border, as shown on the DRG:
> N 49° 00' 03.2520" W 116° 02' 53.6531"
> From a June 2002 email from Brian Butler:
> N 49° 00' 03" W 116° 02' 53"
>
> If there is a monument at the Cananda/USA border, then it
> of course would be definitive as to the tripoint location.
> The Canuck Mountain DRG shows Idaho/Montana Border
monuments
> 2 through 12, with 2 being 1.8956 meters due south of the
border.
>
> If there is no Idaho/Montana border monument at the
Canada/USA
> border, I'm inclined to consider the first coordinate shown
above
> to be the best one at this point, because:
> - Brian's coordinates are only to the nearest second, and don't
> place the waypoint exactly on the border intersection
>
==================================================
====================
>
> --
> Dave Patton
> Canadian Coordinator, Degree Confluence Project
> http://www.confluence.org/
> My website: http://members.shaw.ca/davepatton/