Photo of men processing rocks from a railcar, heating up, putting into bags, near Jasper with Rockies in the background. Based on the title, was able to find reference to tar sands being tested as road covering near Jasper in 1928...so assume this is what we see here.
On back typewritten:
Bituminous sand walks, Jasper, Alberta
Handwritten photo #13011
Comes from the estate of a French collector who died in 1947.
Paper is a bit 'warped'.
11.50 x 16.50 cm
(Red text is an electronic watermark that is not physically part of the photo for sale)
Canadian Tar Sands Tested for Roads
In the far Athabasca country of western Canada, famous in stories of the Royal North West Police, tar sands are being mined to make roads of a new kind in the Jasper National Park, Alberta.
Over gravel roads, the bituminous sands are spread to a depth of about two inches and form a layer similar to asphalt. These sands deposits along the Athabaska River have long been thought to contain possibilities for road building, but this is the first practical test to which they have been subjected
Popular Science December 1928