Just north of Sandbar Lake Provincial Park, a dozen kilometres north of Ignace in northwest Ontario, the landscape is dominated by large room-size boulders that rival the Okotoks erratic. Visitors walking among these behemoths cannot help but be overwhelmed by them.
Dennis Smyk, editor of the local newspaper, ‘The Driftwood,’ explained the discovery. “The Ignace boulder field came to light following forestry operations. In 2004, the boulders stood out above the cutover. Five years later, rapidly growing jack pine began to hide them from nearby access roads. People interested in promotion of the area engaged Sandbar Ontario Rangers to undertake brushing to open up the areas around the boulders and create trails between them.”
He explained what a geomorphologist told the locals about their origin. “These boulders were angular chunks of fractured granite that were removed from the bedrock surface by advancing ice about 10, 000 years ago. This was usually accomplished by freeze-and-thaw processes in which water (often under very high pressure at the base of the ice), makes its way into fractures and freezes, then expands as ice and wedges the fractured blocks apart. The blocks were eventually plucked out and became entrained (frozen) in the ice.
Their size and uniformity (i.e. all granite) suggests that they were derived locally (likely within 5 km) and deposited fairly close to where they originated in bedrock. After the ice retreated, meltwater would flow between the boulders and winnow out all but the largest boulders. The finer material would be deposited farther downstream. The transport in ice and contact with meltwater has smoothed some of the sharp, angular edges that these blocks would have had initially.”
The size of these boulders and their proximity to the Trans Canada Highway means that there is a great deal of interest by boulderers, aficionados of the sport of bouldering, a style of rock climbing undertaken without a rope and normally limited to very short climbs so that a fall will not result in serious injury. It is typically practiced on large boulders or artificial man-made boulders. “The Ignace Boulder Field has been described as “the best bouldering in Canada between the Niagara Glen and the Rockies!” He said, “Visitors will enjoy the experience of seeing the boulders - or climbing them – and can top up their visit by feasting on the namesake blueberries. Keep an eye open for roadside raspberries, too.” You can find these 15 km north of Ignace on Highway 599 (Savant Lake); pass the Park entrance and drive 4.3 km and turn at WGS 84 15 U E607201 N5484213 or N49° 30.064’ W91° 31.166’ (note you are on the 49th N parallel of latitude); drive 0.7 km NNW and then turn WSW and drive less than 0.5 km, the boulders are in sight (north side) scattered amongst the jack pine. These are enormous. You can see the extensive field as large white dots on Google Earth.
Blueberry Boulders - Ignace