Based on a case study of the Ultra-Trail Harricana of Canada (UTHC), this article analyzes the emergence and structuring of trail-running sporting events. The UTHC illustrates just how popular the practice is, and a study of this event offers insights into the relationships that link the event with its environment, partners, and the discipline more broadly. The research data (plural and mixed) will present the unique characteristics that define the event’s evolution, the development strategies, and the challenges and crises faced by its organizers. More precisely, it will highlight the UTHC’s position at the interfaces of sports competition, sports tourism, and the outdoor industry in Quebec.