The different colored areas of the PDF map (dark purple, green, yellow, blue)
represent different geologies within the watershed. The light purple lines are
the county and state boundaries. The white area is outside the watershed.
The watershed, of course, is bounded by the natural ridge line. The map shows
that the light purple Frederick-Washington county boundary deviates eastward
from the natural watershed boundary as it approaches the MDPA state boundary.
Note that the watershed boundary does indeed continue northward into
Pennsylvania as it should. Yes, there is a slight jog at the state boundary,
but there is also a slight jog in the geologies at the state boundary. These
jogs are probably artifacts of slightly discrepant geological data from the two
states. The deviation of the county boundary from the natural ridge line while
still within Maryland, however, is not a mapping accident. It is confirmed by
the text reference to the "very small portion of Washington County" that is
within the watershed.
The USGS map at
http://tinyurl.com/5jme6 shows the county boundary, which seems
to be too far west as judged by Mike Donner's on-site observation of a "shiny
round topped stone post" that he took for the tripoint. Note that the USGS does
show that monument but doesn't think it the tripoint. (I'm withholding judgment
until Mike tells us what it said on that monument, if anything.) The USGS map
does not specifically show the drainage divide, but careful inspection of the
contours will prove that the divide must strike the MDPA boundary west of the
depicted county boundary. The divide runs approximately along the north-south
road through the community of Blue Ridge Summit, Pennsylvania. If you will pan
the map one iteration northward, you will see that the divide runs to the small
hill just southeast of Monterey, then ascends Monterey Peak farther north. This
is not in keeping with the trend of the county boundary as it strikes MDPA.
Lowell G. McManus
Leesville, Louisiana, USA
----- Original Message -----
From: "Michael Kaufman" <mikekaufman79@...>
To: <BoundaryPoint@yahoogroups.com>
Sent: Monday, October 11, 2004 12:06 AM
Subject: Re: [BoundaryPoint] frederick md
>
> In the map in the pdf - is the left edge of the purple
> area supposed to be the ridge? If it is it goes
> straight north. But the USGS ridge line and supposed
> county border slants northeast; it most closely mimics
> the purple county boundary in the pdf map. I think if
> the TP marker were on the pdf it would still fall east
> of the purple line.
>
> --- "Lowell G. McManus" <mcmanus71496@...> wrote:
>
> > At http://tinyurl.com/5jpd4 there is an 18-page PDF
> > of a technical study of
> > water availability in the Monocacy River watershed,
> > which lies east of the Blue
> > Ridge divide in Maryland and Pennsylvania. The
> > second and third sentences of
> > the document state:
> >
> > "This drainage area includes significant portions of
> > Frederick County, Maryland;
> > Carroll County, Maryland; and Adams County,
> > Pennsylvania. It also includes a
> > small portion of Montgomery County, Maryland; a very
> > small portion of Washington
> > County, Maryland; and Franklin County,
> > Pennsylvania."
> >
> > That "very small portion of Washington County"
> > proves that the
> > Frederick-Washington boundary must necessarily stray
> > east of the actual drainage
> > divide. A watershed map on page 3 of the PDF shows
> > such deviation at the
> > boundary's north end as it reaches its tripoint with
> > Pennsylvania. This
> > probably somehow accounts for the discrepancy that
> > you noted on the USGS map.
> >
> > Washington County was created from Frederick County
> > in 1776, and their common
> > boundary was surveyed in 1824. Field notes of the
> > survey are listed in the
> > on-line catalog of the Maryland State Archives.
> >
> > Lowell G. McManus
> > Leesville, Louisiana, USA
> >
> >
> > ----- Original Message -----
> > From: "aletheiak" <aletheiak@...>
> > To: <BoundaryPoint@yahoogroups.com>
> > Sent: Saturday, October 09, 2004 11:04 AM
> > Subject: [BoundaryPoint] frederick md
> >
> >
> > >
> > >
> > > fresh virgin multipoint today class a
> > >
> >
> http://topozone.com/map.asp?lat=39.72417&lon=-77.47167
> > > where the mason dixon line crosses the blue ridge
> > > tho i only just realized they even do cross
> > > yikes
> > > at the interstate tricounty point of franklin
> > county pennsylvania
> > > with frederick & washington counties of maryland
> > > aka frfrwa or mdpa3frfrwa or technically
> > us2mdpa3frfrwa
> > > marked by a shiny round topped stone post in
> > someones side yard
> > >
> > > & tho i cant tell whether the blue ridge itself
> > may continue in the
> > > scramble of mountains still farther north from
> > here
> > > this point does mark the northern limit of the use
> > of the blue ridge
> > > as a state &or county boundary
> > >
> > > in fact frfrwa is exactly 1 tricounty point & 1
> > state line north from
> > > mdvawv on the blue ridge
> > > & all very cleanly so
> > > seeing as the frwa county line completely
> > transsects maryland along
> > > the blue ridge
> > >
> > > all of which you can see if you zoom out
> > >
> > > but if you zoom in
> > > you will find this topo is quite odd
> > > in showing the tripoint & the marker in 2
> > different locations
> > >
> > > on the ground
> > > there is only an ordinary mdpa marker at the
> > tripoint position shown
> > > on the topo
> > > but the true tripoint marker is the one shown
> > about 50 yards farther
> > > east on the opposite side of the road
> > >
> > > marker 92 still farther east is a mason dixon
> > milestone
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > Yahoo! Groups Links
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> >
>
>
>
>
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