Without urgent action against environmental degradation, the forest ravines covering 20% of the city could be reduced to sterile valleys within decades

It can be difficult to keep up with Lawrence Warriner while walking; running, it’s next to impossible. Many of the trails that weave through the ravines near his house in Toronto are well groomed, but for Warriner – a decorated trail runner and coach – the more exciting ones are off the beaten path, tracks only faintly visible to the eye.

He has come to these forests, which rise along the sides of the river valleys that snake through the city, ever since he was a child. He has discovered a secret communal stone grill next to a sandy beach, hidden by trees; he has watched awestruck as a dozen white-tail deer crossed a bridge. He has also seen things he can’t explain, such as a parade of men, women and children, clad in period clothing, walking the woods at dusk with antique rifles slung over their shoulders.