Yosemite National Park accommodates nearly 4 million visitors annually, and the Happy Isles Trail Corridor is among the most popular hiking areas in the park. More than one-quarter of park visitors hike in the Happy Isles Trail Corridor, which provides access to iconic park destinations including Vernal Fall, Nevada Fall, and Half Dome. As a consequence of intensive visitation, coupled with distinct natural hazards, there are more Search and Rescue incidents in the Happy Isles Trail Corridor than in any other part of the park; these incidents include drowning deaths in the Merced River and visitors being swept over waterfalls. Thus, the NPS has an urgent need to understand visitor use and safety in the Happy Isles Trail Corridor.

RSG is working with NPS to conduct visitor surveys, and measure and model visitor use patterns in the Happy Isles Trail Corridor. The purpose of the project is to help the NPS understand visitors’ perceptions of safety, natural hazards, and risk in the Happy Isles Trail Corridor, as well as relationships among visitor use densities, visitor behavior, and safety risks. The information will be used by the NPS to take actions to manage visitor use and improve public safety.