August, 12, 2025
After a decade of renovations at the IATNL/Cabox basecamp at Stowbridges in North Arm, Bay of Islands, chairperson Paul Wylezol finally found time and two willing adventurers to join him on an exploratory trek up nearby Rocky Brook (aka James Cook’s Stone Brook) Canyon. The goal was to establish whether it was possible to hike up or down the 5km long, steep-sided narrow canyon carved into the heart of the North Arm Mountains, one of 4 Bay of Islands Ophiolite Massifs. If possible, it would create additional hiking loops into the mountains from basecamp.
Joining Paul on the trek was perennial Energizer Bunny (Arctic Hare??), backcountry skier and mountain hiker Lew Coty from Vermont who hikes the Long Range Mountains of Western Newfoundland every August after maple syrup season, and Jumpin Jack Flash White, an octogenarian nordique skier and backpacker from Kippens in Bay St. George who never misses an opportunity to challenge himself.
The trio set out from basecamp early in the morning at low tide, and walked .5km along the beach to Rocky Brook. From there they turned northeast and crossed a boulder-strewn spillway for half a kilometer to the mouth of the canyon.
As names go, “Rocky Brook” (aka “Stone Brook”) is about as accurate a description as this brook can have. The entire length of the brook, right out into the bay, is composed of boulder-size rocks generally ranging from 1 to 3 feet in diameter, the ideal size for rock hopping.
And rock hopping it was, back and forth across the brook, finding the path of least resistance over small ledges and around crystal-clear pools.
As with any trek across ultramafic sections of the Bay of Islands Ophiolite, rust-colored peridotite from Earth’s upper mantle dominates the landscape. However occasionally metamorphic derivatives or mafic intrusions, etc create a kaleidosope of color, especially when exposed in direct sunlight.
If it wasn’t already called “Rocky Brook”, a great name for this hidden stream would be Serpentine, after both the abundance of bright green serpentinite (a metamorphic rock derived from peridotite) and the winding path it takes as it chisels its way through the center of the mountain on its way to North Arm.
While Jack and Paul were focussed on rocks, Casting Lew Coty was enjoying the water, testing for brook trout with his telescopic backpacking rod.
However as luck should have it, the size of the fish was directly opposite to Lew’s appetite for adventure, and after 2 hours of brook walking the trio was about to face another!
Though good progress was made climbing up through the canyon, the goal of making it all the way through came to an abrupt end when they rounded a sharp turn to find a 25ft waterfalls surrounded by steep canyon walls.
But not ones to give up easily, Paul and Lew scanned the canyon walls, looking for an acceptible route up and around the falls.
But as is often the case, what looks like an opening far above or below, looks far more challenging, precipitous and slow.
Before long it became evident that there was no moderate or safe route up and around the falls, so the decision was made to keep climbing to the top of the south-facing wall. The only other option was to tuck tail between legs and rock back down the brook.
What was even more impressive than the impassable road block, was how quick Jumpin Jack White took up the challenge to climb to the top of the steep-sided cliff, which at 860 feet was only 10 times his age!
After half an hour of climbing up the side of a “Martian crater”
the intrepid trio finally reached the top.
Though the nutrient-poor slope appeared devoid of life, there were some little surprises along the way.
The next surprise was Lew’s decision to carry on in the heat and circumnavigate the canyon, while Paul and Jack turned west and headed back to basecamp across a 340m high mid-mountain plateau. (North Arm Mountain itself rises to a height of 700m.)
Along the way they passed a section of the Mohorovičić discontinuity, or “Moho,” the geological boundary separating Earth’s crust (generally characterized by light-gray gabbro) from the denser, underlying upper mantle composed primarily of rust-colored peridotite.
They then took a final glance back at the morning’s trek
before descending the mountain and returning to basecamp.
Of course the day wasn’t complete until relaxing on the patio and hearing of Lew’s afternoon exploits, while sharing the morning’s adventure with IATNL/Cabox director Arne Helgeland who stayed back to hold down the fort!
