Mountain regions across Europe face demographic decline and institutional fragmentation that hinder sustainable tourism development. This study analyzes the territorial governance system of the Val Canale and Canal del Ferro valleys (Italian Alps) with the aim of designing a stakeholder-based Organizational Model (OM) to strengthen sustainable tourism coordination in a peripheral mountain context. A qualitative single-case study approach integrates Stakeholder Analysis, Actor-Linkage Matrix, Appreciative Inquiry, and spatial contextualization to examine relational, institutional, and territorial dynamics. The findings reveal a territory rich in environmental and cultural assets—characterized by protected areas and extensive trail networks—yet constrained by fragmented inter-municipal cooperation and limited supra-municipal coordination. Governance fragmentation, rather than resource scarcity, emerges as the primary barrier to coherent territorial development. In response, the proposed multi-level Organizational Model introduces a valley-level coordination unit designed to institutionalize collaborative governance, enhance administrative capacity, and align local initiatives with regional strategies. By operationalizing stakeholder theory within a structured territorial framework, the study contributes to place-based governance literature and offers transferable insights for peripheral mountain regions facing similar coordination challenges.