A young French boy narrates episodic adventures while traveling the continent's great river with early voyageurs and traders, offering vivid sketches of exploration and daily life on the frontier. The stories recount canoe voyages and mapping, encounters and trade with Indigenous communities, hunting and ritual moments, dangers of rapids and wrecks, skirmishes with raiders, and visits to forts and settlements. Each chapter presents a self-contained episode that blends practical travel detail with atmospheric scenes of riverine mystery and hardship.