|
Prospecting
with a
technical
edge
Maximize Your
Gold-Finding
Potential
From Rock & Gem magazine,
Reprinted with permission.
Copyright Miller Magazines Inc. January 2003
|
|
By Karla Tipton
The
dryness of the desert air burned our lungs. The temperature was rising
in Lucerne Valley, California, as our Toyota 4X4 truck rattled over the
sandy dirt road toward the Camp Rock gold placer area. We had been
driving along the same dirt road for 20 minutes, and nothing but scrub
brush and some rocky hillocks could be seen for miles in any direction.
How could we be certain of our location? Was it possible we had missed
our turnoff? Was there a chance we weren't anywhere close to the
destination we had set as our goal?
Not a doubt entered our minds. We were on
target, and we knew it. We had only to look at the pointer on our GPS
screen to know the mining area was exactly 0.56 mile away.
|
Useful Web Sites
for Prospecting with
a Technical Edge
THE BOOK MINE
www.bookmine.com
Visitors to its Old
and Rare Books section can order books about the people and places
that made mining history and maybe find clues to the locations of
forgotten mines.
DELORME
www.delorme.com
High-quality 2-D and
3-D maps are available for purchase on CD-ROM for use with Palm
handhelds, Pocket PC's and laptops.
eBAY
www.ebay.com
An auction Web site
that often features vintage mining publications containing valuable
township/range data of historic locations.
GOLD LEDGE
www.goldledge.com
A collection of new
and historic photographs, maps, book reviews, events, discussion
groups, and articles related to prospecting and mining, as well as
historic mining publications available for purchase on CD-ROM.
TERRA SERVER:
www.terraserver.microsoft.com
Wide-angle and
detailed aerial maps with GPS coordinates, all free.
TOWNSHIP/RANGE
CONVERTER
www.esg.montana.edu/gl/trs-data.html
This converter,
written by Marty Wefeld, is hosted on the University of Montana Web
site and enables township/range coordinates to be converted to
longitude/ latitude for use with a GPS.
|
A new
technique for pinpointing the locations of lost sites is now available
to the small prospector – and many don't even know about it. The technique
makes use of the Global Positioning
System (GPS) and a little old-fashioned book research. Together, these
two things create an enormous resource for discovering hard-to-find
mines, old ghost towns, and other locations lost in the remote past.
In fact, it may turn out that the GPS will
become to the small prospector what electro-optics and remote sensing
has become to large mining companies
– a method for finding the goods
quickly and cheaply.
The GPS consists of 24 satellites in orbit. With
appropriate receiving equipment, the system can be used to determine
geographical coordinates such as longitude and latitude. In addition to
mapping, surveying and monitoring, the GPS is an excellent navigation
tool. And while GPS is an acronym used to refer to the system, it also
commonly refers to the small handheld units that make use of this
system.
Hikers
have been using these handheld devices for years to get around in the
wilderness. Now the prices have dropped
so dramatically that a variety of GPS units can be purchased for
less than $100. Many high-end GPS units even have road and topographical
maps built in.
Our Garmin eTrex Vista cost about $350. In the past year,
recreational prospector Gary Smith has used this little 5.3-ounce unit
to discover a variety of "lost" places. He has found more new locations
to work in the past year than he had in his past decade of prospecting.
"The GPS is now the No. 1 tool that I use," said Smith, who was
recently featured in a New York Times "Circuits" article ("Gold
Prospectors Go Digital," March 14, 2002) for his application of cutting
edge technology to the age-old discipline of prospecting. Smith
primarily hunts for gold in the rich El Paso Mountains near Randsburg,
California.
Like most hobbyists, he dreams about doing recreational prospecting
full-time, but in reality he can't afford to give up his day job, so
precious weekend hours are about all the time he has. "Before I got the
GPS, it would take me most of the day to find what I thought was a good
area to work, and I still couldn't be sure that I had really found it,"
Smith says. "Now I can sit at night, days prior to a trip, plan it all
out, and program it into the GPS. I maximize my time out there, and know
I'm actually looking in the right place. And I get some quality time to
work in the area.
"I do all the research I can," he added. "I go through the books, use
the Internet, and look up locations on the topographical maps that are
available on CD."
The best sources are government publications dating from the 1890s
and the 1930s, especially the latter. "During the Depression, a lot of
people went back to hunting gold, trying to make a living," said Smith.
"There's a lot of information from that time period."
Libraries are excellent repositories for these resources. With the
advent of the Internet, an entire library's catalog is available for
searching online. By using the interlibrary loan service offered at
almost every library in the country, you can check out the books from
remote libraries and pay only the cost of mailing the book to your local
branch.
In addition, some older publications are still available in the
inventories of such agencies as the U.S. Geological Survey. You can
peruse the index of texts online and download an order form if you find
one you want to buy. Rare publications can also be found on eBay and
other auction Web sites. Many bookstores that sell used books also make
their inventories available for searching online. On his Web site,
www.goldledge.com, Smith sells
CD-ROM copies of these public domain
publications, saved electronically in the Adobe Acrobat format and fully
searchable by key word.
Smith found reference to the Camp Rock placer area in an old mining
publication published in 1953 by the State of California Department of
Natural Resources on the mines and mineral deposits of San Bernardino.
Hard to find, but relatively recent in the timeline of California
mining, this publication sold on eBay for a very affordable $30 or so.
Included in this report are descriptions of mining operations and
geological features of this 20,000-square-mile area of the Southern
California Mojave desert, including range and township coordinates. Range
and township information for historical mining areas is the richest ore
of all for those in search of lost gold.
The location of the Camp Rock placer area is cited as being located
at Township 7 North, Range 3 East, Section 28, which would most likely
be abbreviated as T7N, R3E, S28. Knowing the meridian is also important;
in this case, it is the San Bernardino Meridian.
For those who use topographical maps, township/range/section
information should be familiar. How this mapping system came into use
may be more of a mystery, however. The range and township coordinate
system was developed to map the area of the United States west of the
Ohio River, beginning in 1784, as new territories were settled. In each
area to be surveyed, a reference point was established from astronomical
observations upon which the survey would be based. From the reference
point, a true north-south line was projected to the limits of the area
to be surveyed. Also from the reference point, an east-west line,
following a true parallel of latitude, was projected to the limits of
the area. Townships, as close to six miles square as possible, were
formed parallel to the reference lines. The townships were further
divided into one-mile-square sections. A column of townships extending
north-south was called a range and a row of townships running east-west
was called a tier (a term eventually replaced by the word "township").
Sections can be quartered repeatedly to define a position. It is these
township/range designations that appear as numbers and letters on the
edges of topographical maps. Original Spanish land grants were excluded
from the range and township survey.
Before the township and range information can be used with your GPS,
it needs to be converted to longitude and latitude. A good converter,
available online from Montana State University (www.esg.montana.edu/gl/trs-data.html),
provides the longitude/latitude equivalent of the township and range
coordinates, which in this case is 34.66694, 116.67138 (also read as
34°, 40', 1.0" N; 116°, 40', 17.0" W).
The converter, a computer program written by Marty Wefald, provides
nearby "named" places, and a Web link to that position on the Microsoft
TerraServer (www.terraserver.microsoft.com). The satellite images of the
United States available on the TerraServer can be zoomed in to amazing
detail, revealing recognizable structures and rock formations.
Range and township information can also be entered into mapping
software, such as Topo USA 4.0 or 3-D Topo Quads (by state), available
on CD-ROM from Delorme (www.delorme.com). This provides the longitude
and latitude coordinates, as well as a printable map you can use to get
to your targeted location. With additional accessory cables to interface
with your PC and sufficient built-in memory in the GPS, the map data can
be downloaded right into your handheld unit.
The Topo USA software may be considered a bit pricey by some
standards (about $100), so there is a cheaper way. Once the longitude
and latitude coordinates have been determined, these can be programmed
directly into the GPS as a destination point, called a "waypoint" in GPS
terminology. By studying a more traditional paper topographical map, you
can then calculate additional township/range coordinates along the route
you plan to take, and enter these into the GPS as additional
"waypoints," creating a kind of portable electronic breadcrumb trail.
All that's left is to turn on the GPS's navigation function and switch
to the device's map screen, hop in your 4X4, and start driving.
As you travel, a line capped with an arrow is drawn on the GPS
liquid-crystal display screen indicating how closely you are following
the route mapped by your programmed waypoints. You can expect to veer
off slightly, as roads are not always mapped with precision on topo
maps. Dirt roads can also change course somewhat over the years as they
are washed out and remade. But if you turn the wrong direction entirely,
you'll know immediately, because the arrow will be traveling in the
opposite direction from your destination. The tracking arrow and your
final waypoint will eventually coincide as you reach your destination.
GPS accuracy is based on the relationship of the device to at least
three satellites, known as triangulation. To triangulate, a GPS receiver
measures distance using the travel time of radio signals. In 2000,
restrictions affecting the accuracy of GPS consumer models were
lifted by the Defense Department, which operates the system. As a
result, even the lower-end GPS units have accuracy to 30 feet under the
best operating conditions. In addition, the closer you are to the
equator, the more likely your GPS will be able to receive signals from
Wide Area Augmentation System (WAAS). A ground- and space-based system
designed for airplane guidance, WAAS signals improve accuracy to within
15 feet. So far, there are only a few deployed WAAS satellites that are
in a fixed orbit around the equator and appear close to the horizon in
North America. Ground-based GPS units have difficulty picking up the
signals in terrain containing trees or other tall obstructions.
Since we were in the high desert of Southern California with
virtually no obstructions, the WAAS system enhanced the accuracy of our
GPS. As we closed in on the Camp Rock placer area, the dirt road ended
at a group of craggy granite hills. Workings of old mining operations
dotted the landscape. Throughout the general area, there were historic
structures and equipment, and several tunnels. A claim marker denoting
the location confirmed that we had indeed arrived at our destination.
Without fuss and without wasting time on aimless wandering over unknown
trails, we had reached our goal.
Some earlier research on the Bureau of Land Management Web site (www.blm.gov/lr2000)
had informed us that while one corner of the section was actively
claimed up, there were many nearby areas no longer under legal claim and
available for us to work. Now, the many hours that remained in the day
could be used for the real work of finding gold.
Entire cultures are springing up around the use of the GPS. Groups of
techno-literate genealogists now use it to search for lost cemeteries
and family homesteads. And there's a group of high-tech treasure hunters
who do "geocaching," a new pastime that usually includes four-wheeling,
hiking and searching for a "cache" of modern-day souvenirs left by other
geocachers.
The practical application of new technologies to our outdoor pastimes
can sometimes be difficult to discern. And perhaps something of the
romance of treasure hunting is lost when we give up our magnetic compass
and "X-marks-the-spot" paper map. However, there's no denying that the
use of the GPS in conjunction with traditional researching methods might
just lead you to the real "pay dirt."
|