|Photo: Courtesy of DStretch.com|
New technology reveals details of rock inscription left by Simon Fraser
By Brad Himour
In 1806, explorer and fur trader Simon
Fraser embarked on a journey that
would see him explore territory west of
the Rocky Mountains that no European
had seen before and travel down the great
river that now bears his name. That same
year, Lewis and Clark completed their
famous odyssey west on behalf of the United States, reaching the Pacific. Now
it was Fraser’s turn to find his way to
the coast on behalf of the North West
Company and, by proxy, the British
Crown. At stake was nothing less than
the frontier of a “new” continent, where
commerce and settlement would eventually
follow on a massive scale.
Fraser spent the winter of 1806-07
along the shores of what later became
known as Stuart Lake, where he and
assistant John Stuart established Fort
St. James. The now-reconstructed furtrading
post is today a national historic
site managed by Parks Canada. And some
200 years after its creation, local claims
persisted that Fraser had etched his name
into an exposed rock face beside two
prominent First Nations pictographs.
If proven authentic, the site would join
older “signatures” left by explorers Sir Alexander Mackenzie and Samuel
Hearne as Canadian equivalents of the
inscription made by Lewis and Clark
at Pompeys Pillar in Montana, the
only physical trace of their journey
that remains on the landscape today.
Unfortunately, the Stuart Lake inscription had faded significantly. Although the visible remains were tantalizing, it was impossible to determine
exactly what was painted on stone.
Then, in 2005, American rock-art researcher Jon Harman developed a new technology for examining rock art using the digital enhancement of photographs.
Harman’s DStretch program — a plug-in to ImageJ, a U.S. government program that’s available free online — uses an image-enhancement algorithm called decorrelation stretch, which was developed at NASA to enhance contrast in remote-sensing images. Harman modified the algorithm for rock-art
images. It can make pictograph pigments visible that are too faint to be seen by the naked eye.
The BC Heritage Branch had several photographs of the alleged Simon Fraser inscription on file. Once DStretch software
became available, it didn’t take long for researchers to test the new technology on an old site.
The results were immediate and striking. The name “Simon F” and, beneath it, “1806” leapt off the screen.
The Royal BC Museum provided samples of Fraser’s handwriting from his personal letters. The samples matched
the pictograph. It was official: Canada had a new landmark.
It seems fitting that Fraser, the namesake for so many places in British Columbia, inscribed his name among
the many First Nations pictographs on the cliffs above Stuart Lake. And with a little help from technology, we can view
it today almost as clearly as it would have appeared more than two centuries ago.
Brad Himour is an archaeologist with Parks Canada in Calgary.