The Saguenay Fjord is not carved by its own river. Glaciers a kilometre thick gouged the trench during the last ice age, and the meltwater river merely inherited it — a valley 105 kilometres long, 275 metres deep at points, its floor lying well below sea level. That geology explains the whales. Where the fjord's dark, tannin-stained surface water meets the cold saline mass of the St. Lawrence estuary, an underwater sill forces deep currents upward. The upwelling carries krill and capelin into the light. Minke, fin, humpback and, in some summers, blue whales follow the food north each spring. The beluga, alone among them, never leaves; a resident population of roughly 900 winters here in the ice, the southernmost such group on Earth. Any whale watching tour in tadoussac and exploration of the saguenay fjord is, in effect, a tour of that collision of waters. Human settlement followed the same logic. Innu peoples gathered at the river mouth for millennia before Basque whalers rendered blubber on these shores in the sixteenth century. Pierre Chauvin raised a trading post at Tadoussac in 1600, eight years before Québec City itself — making the village one of the oldest continuously occupied European sites in the Americas. The fur trade ran through it; the whaling industry nearly emptied the estuary by the 1900s. Protection came late. The Saguenay–St. Lawrence Marine Park, created in 1998, was Canada's first park to protect a marine environment alone, and it now governs approach distances, engine speeds and vessel numbers throughout the observation zone. What remains is a landscape of severe simplicity. Baie-Sainte-Catherine and Pointe-Noire frame the fjord's mouth. Cap Trinité rises 350 metres from the water, its 1881 statue of Notre-Dame du Saguenay carved in three pine sections and hauled up by rope. Boreal forest runs to the cliff edge; black bears work the tidal flats at dusk. The red roof of the Hôtel Tadoussac, standing since 1864, remains the village's fixed point on every horizon. Modern croisière aux baleines et fjord du Saguenay operators depart from the same working quay that once received schooners. Zodiacs sit low and fast; larger vessels carry upper decks and enclosed lounges. Several Tadoussac whale watching boat tours pair the estuary crossing with a run up the fjord walls. Booking a whale watching tour in tadoussac and exploration of the saguenay fjord tour today means entering a protected corridor that took four centuries of extraction, and one of restraint, to arrive at.