TECHNOLOGY

Photo: Courtesy of DStretch.com

Historic graffiti

New technology reveals details of rock inscription left by Simon Fraser

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.