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Environmental Impact Statement for Restoration of the Mariposa Grove of Giant Sequoias, Yosemite National Park, Madera, Mariposa, Mono, and Tuolumne Counties, CA

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National Park Service.


Notice of intent to prepare an Environmental Impact Statement.


The National Park Service (NPS) is preparing an Environmental Impact Statement (EIS) for the Restoration of the Mariposa Grove of Giant Sequoias in Yosemite National Park. This EIS addresses implementation of actions called for in the 1980 General Management Plan (GMP), presenting comprehensive design alternatives for restoring natural conditions in the Mariposa Grove, as well as improving visitor experience and access within the Grove and at the nearby South Entrance to the park. The NPS is initiating public scoping and consultation with interested members of the public, agencies, and federally recognized American Indian Tribes traditionally associated with the area to help identify topics, issues, and concerns for consideration in the EIS.


Comments must be received by January 3, 2012.

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In 1864, Congress passed landmark legislation preserving both the Mariposa Grove of Giant Sequoias and the Yosemite Valley. This was the first time Congress set aside public lands for the express purpose of preserving scenic and natural values, stating that these areas “shall be held for public use, resort, and recreation * * * inalienable for all time” (Act of June 30, 1864, 13 Stat. 325). Giant sequoia groves occur sporadically on the western slope of the Sierra Nevada as remnants of more extensive forests that existed thousands of years ago. These impressive trees are known for their massive size and longevity. The Mariposa Grove comprises about 500 mature giant sequoia trees in an upper and lower grove. It is the largest of three giant sequoia groves within the park. Distribution of the trees is limited by several factors including surface water, typically supplied by melting snow; soil and air moisture; temperature; and ground water. Giant sequoias have expansive but shallow root systems that can reach up to one hundred feet from the base of the tree. Fire plays an important role in giant sequoia ecology, creating canopy openings and releasing soil nutrients needed for seedling establishment. Fire scars on the trees indicate that fires occurred at intervals of approximately 3-15 years within the Mariposa Grove until the late 19th century.

The Mariposa Grove is home to several special-status species, including the pacific fisher (Martes pennanti, a candidate for federal listing as a threatened or endangered species), California spotted owls (Strix occidentalis occidentalis), Bolander's woodreed (Cinna bolanderi), mountain lady's slipper (Cypripedium montanum), and Coleman's piperia (Piperia colemanii). Cultural resources in the area include archaeological resources and several historic properties either in, or eligible for listing in, the National Register of Historic Places. Historic resources include (1) the Mariposa Grove, a historic district that includes the loop road, several trails, the Civilian Conservation Corps-era comfort station, and the Grove Museum (individually listed), and (2) the South Entrance Station, a historic district that includes the comfort station, ranger residence/garage and the entrance checking station. The Mariposa Grove Road will be assessed for its eligibility for listing in the National Register as part of the project. Non-historic structures and sites within the Grove include the parking areas, gift shop, ticket booth, tram staging area, fueling station, vault toilets, shuttle stops and bus parking areas, several trails, and communications equipment.

Site Management History: Paved roads, parking areas, a campground, and other infrastructure were constructed within the Mariposa Grove from the 1930s to the 1970s. Since then, management practices have evolved along with our understanding of ecology and giant sequoias. After nearly a century of fire suppression, prescribed fire was reintroduced to the Mariposa Grove in 1971, as resource managers recognized that heavy fuel build-up could threaten its survival. Growing concerns about visitation impacts also led to the decision to prohibit private vehicles in the Upper Grove. In the 1980 General Management Plan (GMP), Yosemite National Park outlined goals and actions to protect and restore the Mariposa Grove and improve the nearby south entrance to the park. Some projects have been implemented, such as removal of the campground and lodge. However, several major actions have yet to be fully designed or implemented, such as relocating parking from the Lower Grove, improving facilities, upgrading utilities, and redesigning the South Entrance Station.

Purpose and Need: Comprehensive actions are needed to ensure that the Mariposa Grove continues to thrive and provide inspiration and enjoyment for future generations. Primary goals of this project are to restore degraded habitat and natural processes critical to the long-term health of the Mariposa Grove, and to improve the overall experience for visitors. Existing conditions affecting the health of the Mariposa Grove include (1) roads and other infrastructure are disrupting natural water flows, (2) facilities in the Lower Grove—a parking lot for over 100 vehicles, a tram staging area, fueling station, fuel storage tanks, generators, and a gift shop—are encroaching on sequoias and their habitat, and (3) foot and vehicle traffic have compacted soils and exposed shallow sequoia roots. Stressed trees are less resilient and more susceptible to external threats such as disease, wildfire from surrounding areas, and effects from climate change.

Existing conditions affecting the visitor experience include (1) inadequate information exists to properly orient visitors upon arrival to the park or the Mariposa Grove, (2) road configuration at the South Entrance and entrance to the Mariposa Grove is confusing, (3) the parking lot fills to capacity early in the day, forcing temporary closures of the lot and road, (4) long lines form at the kiosks and intersection as visitors attempt to get information, find parking, or turn around due to lot and road closure, (5) shuttles from Wawona to the Mariposa Grove are often already full when they arrive at the South Entrance Station shuttle stop, and (6) trails and facilities need improvements for accessibility.

Conditions affecting visitor and employee safety include (1) pedestrian crossings to and from the facilities and parking are undefined and hazardous amid the traffic congestion, (2) small entrance station kiosks have insufficient space for employee safety, accessibility, or comfort while working long shifts, (3) multiple left turn lanes crossing one another at the South Entrance Station Start Printed Page 75559increase potential for accidents, and (4) large vehicles have difficulty making the turn to exit the park, sometimes striking barriers and kiosks.

To address these issues, the NPS will be developing a range of alternatives to restore the Mariposa Grove and improve visitor experience, consistent with goals outlined in the GMP. Grove restoration treatment plans will be informed by existing and ongoing scientific research and monitoring. Site design alternatives may include actions such as (1) relocating the parking lot away from the giant sequoias, (2) improving trails and transportation access within and to the Grove, (3) repairing, replacing, and/or removing deteriorating infrastructure and utilities, (4) redesigning traffic circulation, and (5) accommodating parking in the vicinity of South Entrance, with visitor orientation information and shuttle stops.

The EIS will describe and analyze a no-action alternative (maintain current management, roads, and facilities) and several action alternatives for restoring the health of the Mariposa Grove. Alternatives will be developed consistent with applicable federal, state, and local regulations, NPS policies, and relevant park plans, including the Merced River Plan (in progress). All alternatives will include methods to minimize or avoid adverse effects to natural, cultural, and historic resources, and the “environmentally preferred” course of action will be identified.

Written comments may be submitted online at:​mariposagrove. Alternately, letters may be mailed to the Superintendent, Attn: Mariposa Grove EIS, P.O. Box 577, Yosemite, CA 95389. Comments may also be submitted in person, during business hours, to the Superintendent's Office in the Valley Administration Building or the Office of Environmental Planning and Compliance, 5083 Foresta Road, El Portal, CA, or may be hand-delivered at the open house.

To learn more about the proposed restoration, the public is invited to attend any of the regularly scheduled park planning open houses. In addition, current project information will be posted at​yose/​parkmgmt/​mgrove.htm, or may be obtained by telephone at the Yosemite Office of Environmental Planning and Compliance (209) 379-1002.

Before including your address, phone number, email address, or other personal identifying information in your comment, you should be aware that your entire comment—including your personal identifying information—may be made publicly available at any time. While you can ask us in your comment to withhold your personal identifying information from public review, we cannot guarantee that we will be able to do so.

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Dated: November 4, 2011.

Cynthia L. Ip,

Acting Regional Director, Pacific West Region.

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[FR Doc. 2011-31024 Filed 12-1-11; 8:45 am]