Half Dome visitor use management: Optimizing park operations and visitor experiences through empirical evidence

The Half Dome Trail (HDT) hike has long been the setting of an iconic experience in Yosemite National Park. The trail takes visitors up the only route accessing the summit without technical climbing. Over time, it has transformed from a historic multiday wilderness experience to an ambitious, and frequently epic, day hike. This 16-mile (26 km) hike ascending 4,000 ft. (1,219 m) is a significant undertaking that ends with the last 400 ft (122 m) of the ascent exposed and on a cables structure. In recent years as visitation has increased, numerous search-and-rescue incidents have taken place on and around the cables. This trend led park management to investigate visitor use on the trail system leading to Half Dome, including behaviors on the cables. This article describes a series of scientific investigations applied to inform and further frame management of visitor use along the HDT. Notably, results from visitor use measurement, simulation modeling, and monitoring of visitor movements provide a basis for standards that frame acceptable conditions.