Observational Study of Grand Canyon Rim-to-Rim Day Hikers: Determining Behavior Patterns to Aid in Preventive Search and Rescue Efforts.

Introduction: Grand Canyon National Park has seen an increase in visitors traversing the canyon from rim to rim (R2R) in a single day. R2R hikers travel over 33.8 km (21 mi) over 3300 m (11,000 ft) of elevation change and endure large temperature changes.