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Skip the
lesson and go directly to the index map.
In
1851 public surveys began in the Oregon Territory.
The
Initial Point was chosen as:
Lat.: 45.52 N Lon: -122.7425 W
Based on this intersection a grid of squares, six miles
on a side, is laid out. Each six mile square is called a
Township. They are named for their distance from the
initial point. Thus we have Township 1 North of Range 1
East of the Willamette Meridian, and successively as you
progress further from the Initial Point.
Within each township there
are 36 1-mile square sections ,
which are further broken down into 1/4 sections, which
are themselves broken down, etc. ad infinitum for legal
descriptions of property.
More detailed info can be found here.
Virtually all of the early survey maps have been preserved
and digitized by the BLM (formerly the Government Land
Office). They are referred to as GLO Maps and they are
available to the public online in various places.
We have created a subset of these maps which contains the
trail of Lewis and Clark in Washington and Oregon. We
have also created a grid map showing which townships are
involved in the trail.
We can use these maps to help us better understand the
river seen by Lewis and Clark and early settlers. One
excellent example is the area around Wallula, WA, where
we can see the old Indian trail used by Lewis and Clark,
as well as the shape of the Columbia River before the
dams. it also shows the "old H.B. Fort Walla Walla."
by overlaying this map on a modern
topo map, we can see the significant differences
between the modern and historical river at this point.
BLM has invented a nomenclature
for their survey maps, which at first seems confusing.
They use a 3 digit number for township and range. This
allows for fractional townships. Here is the
nomenclature for the map above. Township 7 north of
Range 31 East of the Willamette Meridian:
t070n310e_001.jpg.
Most townships have more than one
map. There are often partial surveys and other
information. Generally speaking the map labeled
***_001.jpg is the one most often used. I have included
them all, for your information
There are several ways to find the
township and range for any area.
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The
Graphical Locater from Montana State University
gives a wealth of information per click.
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The
L&C township locator from Rob Heacock
may be downloaded and used to find T&R for named
areas. Also includes the names of pertinent USGS 7 1/2
minute topoquads
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A full township map of WA & OR
is also available for download. (1.7 Mb) or
Use the
grid below to find the area you want within the
brown outline. Write down the range and township you
want, then
go to the maps.. You will go through a
couple of directories to get to the maps you want.
[West
Index Map] [Middle
Index Map]
[East
Index Map]
Take
note of the Range & Township and then
get the maps.
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