Half Dome, one of Yosemite National Park's most familiar sights, rises nearly 5,000 feet above the Valley floor. In 1865, this granite dome was considered "perfectly inaccessible," but thousands of Yosemite hikers now reach the top each year by following a strenuous trail from the Yosemite Valley floor. The final 400-foot ascent, up the peak's steep east face, follows a pair of steel cables raised on posts that lead to the breath-taking summit. This cable route was constructed in 1919 by the Sierra Club for visitors without technical rock climbing ability. Using the Half Dome Cables is a unique experience, and it has become one of the most popular hikes in Yosemite National Park.
How many people are too many for a wilderness trail? Half Dome, one of the most popular attractions in Yosemite National Park, lies in designated wilderness. In 2008, up to 1,200 people a day tackled the famous trek up the cables; the high level of use led to both safety and environmental concerns.
To address impacts caused by increased visitor use of the Half Dome trail, the National Park Service (NPS) developed a management plan. The purpose of the plan was to provide long-term stewardship of the Half Dome route in a manner that is consistent with the Wilderness Act and the National Park Service Organic Act.
More specifically, the goals of the plan were to:
Data gathered during an interim permit system enacted in 2010 will helped to inform the plan. After a thorough planning process involving public participation a final environmental assessment and Finding of No Significant Action was finalized in late 2012.
Finding of No Significant Impact
What studies are taking place on the Half Dome trails?
In all of these studies, survey research is meant to gauge visitor exposure to information, awareness of safety issues, perceptions of crowding, perceptions of risk, and other factors that influence a safe and enjoyable visit. This information is complemented by other standard survey research questions such as visitor demographics.
Yosemite National Park decided to implement the Half Dome Cables Day Use Interim Permit Program in 2010 for visitors ascending the Half Dome cables on Fridays, Saturdays, Sundays, and holidays. The Half Dome Trail Visitor Use Monitoring Report [1.4 MB PDF], completed in November 2010, documents the effects on visitor use conditions on and around Half Dome from the permit system in an attempt to limit daily visitor use to 400 people per day. This report focuses on the descriptive data regarding visitor densities, travel times, and overall daily visitor-use levels and discusses the documented effects of this management action to use levels during weekdays (Monday through Thursday). The report is the first of two years of monitoring visitor-use conditions on the Half Dome Trail in tandem with this planning process to determine a long-term management strategy.
2008 - 2009
In 2008, studies on the Half Dome Cables Trail combined computer-based simulation modeling and survey research to understand impacts to the natural environment and social conditions on the trail and help define a baseline for current visitor experience conditions. These studies occurred in July and August 2008 with the Half Dome Cables Modeling and Visitor Use Estimation Final Report: Yosemite National Park [6.3 MB PDF] completed in April 2009. The primary objective of the computer modeling is to understand the connection between the number of people using the trail and the amount of time spent on the cables. Delay times were collected on the trail as well as time spent at the summit. With these data, the computer model is able to predict crowding based on people per viewscape and people at one time on the trail. This information provides important baseline data for projections of use of the cables based on the amount of people arriving at the Happy Isles Trailhead.
How will these studies help park managers?
Science-based visitor use modeling and social science research allows park management to better understand preferred visitor experiences, use levels, and safety on the cables as well as on the trail networks leading to the cables. Baseline data are useful in planning for the future of the park, monitoring use over time, and informing park staff about visitor use trends and attitudes. The computer simulation model allows management to observe a full spectrum of conditions by running hypothetical simulations to understand how use levels might affect social and natural conditions in this region of the park.
Last updated: December 2, 2019