Protected Natural Areas (PNAs) play a crucial role in driving rural and local development within their regions. Certain PNAs feature iconic mountain peaks that serve as major attractions for mountaineering tourism. While economic impact stands as a fundamental component within the triad of sustainable tourism, and mountaineering significantly propels economic growth in destination areas, a noteworthy gap exists in the available data concerning the impact and determinants of spending within this context. This study, conducted among mountaineering visitors in PNAs, aims to analyse the distribution of spending overall and by mountain peak and to identify the determinants influencing direct spending. The research involved a sample of 562 mountaineers who ascended five Spanish peaks during the summer of 2020. The investigation revealed an average expenditure of approximately €10.62 per mountaineer. Logistics regression identified a total of six variables influencing spending. Remarkably, the research revealed overcrowding
as a substantial predictor of mountaineering expenditure; specifically, the perception of overcrowding correlated with decreased spending. Understanding how visitors perceive and react to crowded environments is crucial for devising strategies that foster local economies and protect the natural environment of these destinations. The study’s findings are relevant to mountaineering economic management in PNAs.