The Stygian Shadowdragon (Neurocordulia yamaskanensis) was the subject of an investigation in 2017 at the foot of Mount Yamaska, in the slow and winding course of the Black River, located in Saint-Pie, Montérégie. This is the type locality of the species, discovered more than 140 years ago by Reverend Léon Provancher, and which had not been explored since at the odonatological level. The collect of exuviae and crepuscular observations of adults have shown that a population of the species is still present in the Mount Yamaska area. This discreet dragonfly, rarely seen in Québec, usually goes unnoticed because of its crepuscular behavior. This return to the origins of Provancher’s discovery in 1875 is a nod to his lasting work, which continues through his magazine Le Naturaliste canadien, which in 2018 marks its 150th anniversary.