National Park Service U.S. Department of the Interior Yosemite National Park Yosemite, California Half Dome Trail Stewardship Plan Environmental Assessment January 2012 Half Dome Trail Stewardship Plan Environmental Assessment Yosemite National Park Lead Agency: National Park Service U.S. Department of the Interior ABSTRACT In 1964 Congress passed the Wilderness Act, creating the National Wilderness Preservation System, “to secure for the American people an enduring resource of Wilderness.”1 In 1984, Congress designated 95% of Yosemite National Park, including Half Dome and the Half Dome Trail, as a part of the National Wilderness Preservation System. Many Yosemite visitors travel into the wilderness to seek the beauty, solitude, and challenge that Congress sought to protect with wilderness designation. The California Wilderness Act of 1984 (Public Law [PL] 98–425) directs the National Park Service (NPS) to manage areas designated as wilderness according to provisions of the Wilderness Act of 1964. Half Dome is an iconic, granite peak visible from many spots in Yosemite National Park, and rising 5,000 feet above the Yosemite Valley floor in one dramatic sweep of sheer rock. Its summit is a goal for a broad cross section of the public; beginning and experienced hikers, first-time and lifelong park visitors, an array of ethnicities and cultures, children to grandparents, and people from all around the world. For many, this may be their first hike in designated wilderness. The combination of the long hike, an exhilarating, exposed ascent of the cables, and a spectacular view from the summit can combine to be a highlight of a person’s summer or even a life-changing event. The popularity of the Half Dome Trail has resulted in crowding along the Trail and the summit and adversely impacts wilderness character of the area by compromising visitors’ opportunities for solitude. High use levels also adversely impact wilderness character due to adverse impacts to natural resources. Crowding has raised concerns about the safety of both the public and that of rescue personnel on the cables. Crowding subjects hikers to long travel times and delays in ascending and descending the Half Dome Cables and may prevent them from getting down from the exposed portion of the Trail in a timely manner so as to avoid rain and lightning storms. These conditions on the Trail, as they existed at the start of this EA process, are counter to the Wilderness Act and National Park Service policy. The EA determines how to best manage the Half Dome Trail in accordance with the above law and policy. This document presents and analyzes five alternatives for public review and comment regarding wilderness character and risk management on the Half Dome Trail, in accordance with the National Environmental Policy Act and the National Historic Preservation Act. The No Action Alternative represents retaining the cable system and continuing to manage the Half Dome Trail as it was through 2009, without day-use limits. The No Action Alternative would result in impacts to both visitor safety and wilderness character, thereby violating NPS policy and is being carried forward as an alternative solely to demonstrate baseline conditions and allow direct comparison with the action alternatives. Therefore, the following four action alternatives represent a reasonable range of options to satisfy the purpose of and need for the project, while also meeting all relevant legal requirements: Alternative B: 400 People per Day (Minimum Management Action) Alternative C: 300 People per Day (Preferred) Alternative D: 140 People per Day Alternative E: Remove the Cables 1 Public Law 88-577 (16 U.S. C. 1131-1136) Table of Contents Table of Contents EXECUTIVE SUMMARY ........................................................................................................................................................ iv INTRODUCTION ......................................................................................................................................................................................... iv PURPOSE AND NEED FOR ACTION ................................................................................................................................................... iv OVERVIEW OF THE ALTERNATIVES ................................................................................................................................................ v ACTIONS COMMON TO ALL ALTERNATIVES ............................................................................................................................... ix ORGANIZATION OF THIS ENVIRONMENTAL ASSESSMENT ................................................................................................. x CHAPTER 1 PURPOSE AND NEED .................................................................................................... 1-1 INTRODUCTION ...................................................................................................................................................................................... 1-1 PURPOSE OF THIS PROJECT ............................................................................................................................................................. 1-2 NEED FOR THIS PROJECT................................................................................................................................................................... 1-2 PROJECT SCOPE ...................................................................................................................................................................................... 1-2 BACKGROUND ......................................................................................................................................................................................... 1-2 POLICY AND PLANNING CONTEXT................................................................................................................................................ 1-6 PUBLIC INVOLVEMENT .................................................................................................................................................................... 1-10 CHAPTER 2 ALTERNATIVES.............................................................................................................. 2-1 DEVELOPMENT OF ALTERNATIVES ............................................................................................................................................. 2-2 ALTERNATIVES CONSIDERED AND DISMISSED .................................................................................................................. 2-13 IDENTIFICATION OF THE MINIMUM MANAGEMENT ALTERNATIVE ...................................................................... 2-16 IDENTIFICATION OF THE PREFERRED ALTERNATIVE ................................................................................................... 2-16 ENVIRONMENTALLY PREFERRED ALTERNATIVE ............................................................................................................. 2-16 SUMMARY OF ENVIRONMENTAL CONSEQUENCES ........................................................................................................... 2-17 CHAPTER 3 AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES ........ 3-1 INTRODUCTION ...................................................................................................................................................................................... 3-1 IMPACT TOPICS CONSIDERED IN THIS ENVIRONMENTAL ASSESSMENT ................................................................. 3-1 IMPACT TOPICS NOT INCLUDED IN THIS ENVIRONMENTAL ASSESSMENT ............................................................ 3-1 IMPACT SIGNIFICANCE DETERMINATION ................................................................................................................................ 3-2 WILDERNESS............................................................................................................................................................................................ 3-3 VISITOR EXPERIENCE ....................................................................................................................................................................... 3-11 VISITOR EXPERIENCE – ALTERNATIVE A – NO ACTION ................................................................................................. 3-12 PUBLIC SAFETY– MANAGING PERSONAL RISK .................................................................................................................... 3-15 NATURAL RESOURCES ..................................................................................................................................................................... 3-19 NATURAL RESOURCES – ALTERNATIVE A – NO ACTION ................................................................................................ 3-23 CULTURAL RESOURCES AND HISTORIC PROPERTIES ..................................................................................................... 3-26 CULTURAL RESOURCES AND HISTORIC PROPERTIES – ALTERNATIVES A, B, C and D ................................... 3-28 PARK OPERATIONS ............................................................................................................................................................................ 3-28 PARK OPERATIONS – ALTERNATIVE A – NO ACTION .....................................................................................................