The Mountain Sentinels Collaborative Network is composed of scholars, non-governmental and governmental organizations, and stakeholders working towards the sustainability of mountain environments and communities worldwide. Our guiding questions include: How will mountains respond to gradual and abrupt changes impacting land, water, peoples and livelihoods? Will they be resilient and continue to deliver vital ecosystem services? What transformations are needed and which adaptation pathways lead to healthy and desired futures across mountain regions worldwide? We are helping to develop tools and protocols to address these questions and sharing lessons learned across mountain systems worldwide. Some examples of our work include using and developing coupled social-ecological models to explore current and future conditions in mountains and as tools for communication, learning and decision-making; identifying best practices for successful transdisciplinary approaches effectively linking science with policy and practice to better address critical challenges and problems in mountains; holding webinars regarding topics of mountain sustainability; disaster risk reduction; educational activities; linking science with policy; transdisciplinary approaches; participatory social-ecological modeling.