Merced Wild and Scenic River Comprehensive Management Plan / DEIS 12-1

12. GLOSSARY AND ACRONYMS 

GLOSSARY OF TERMS 

100-year floodplain: The area along the river corridor that would receive floodwaters during a 

100-year flood event. A 100-year flood event has the probability of occurring 1% of the time during 

any given year. If a 100-year flood event occurs, the following year will still have the same probability 

for occurrence of a 100-year event. For the purposes of this plan, the 100-year floodplain also includes 

wetlands and meadows associated with the hydrologic and ecological processes of the river. 

1982 Secretarial Guidelines for Wild and Scenic Rivers: The 1982 Interagency Guidelines on the 

Wild and Scenic Rivers Act (also referred to as Secretarial Guidelines) provide guidelines on the 

evaluation, classification, and management of rivers designated as Wild and Scenic within the U.S. 

Departments of Agriculture and the Interior. The section of the guidelines on management of Wild 

and Scenic Rivers addresses carrying capacity and public use, as well as development of facilities and 

other management issues. 

Adaptive management: A process that allows the development of a plan when some degree of 

biological and socioeconomic uncertainty exists. It requires a continual learning process, a reiterative 

evaluation of goals and approaches, and redirection based on increased information and changing 

public expectations. 

Affected environment: Existing biological, physical, social, and economic conditions of an area that 

are subject to change, both directly and indirectly, as a result of a proposed human action. 

Alluvial: An adjective referring to alluvium, which are sediments deposited by erosional processes, 

usually by streams. 

Alluvium: A general term for clay, silt, sand, gravel, or similar unconsolidated rock fragments or 

particles deposited during comparatively recent geologic time by a stream or other body of running 

water. 

Alternatives: Sets of management elements that represent a range of options for how, or whether to 

proceed with a proposed project. An environmental impact statement analyzes the potential 

environmental and social impacts of the range of alternatives presented. 

Archeological resources: Historic and prehistoric deposits, sites, features, structure ruins, and 

anything of a cultural nature found within, or removed from, an archeological site. 

Area of potential effect: The geographic area or areas within which an undertaking may directly or 

indirectly cause changes in the character or use of historic properties, if such properties exist. The area 

of potential effect is influenced by the scale and nature of the undertaking and may be different for 

different kinds of effects caused by the undertaking. 
GLOSSARY AND ACRONYMS

12-2 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Bed: Refers to the relatively flat or level bottom (substrate) of a body of water, as in a lakebed or 

riverbed. 

Best Management Practices: Effective, feasible (including technological, economic, and institutional 

considerations) conservation practices and land- and water-management measures that avoid or 

minimize adverse impacts to natural and cultural resources. BMPs may include schedules for activities, 

prohibitions, maintenance guidelines, and other management practices. 

Biodiversity: Biodiversity, or biological diversity, is generally accepted to include genetic diversity 

within species, species diversity, and a full range of biological community types. The concept is that a 

landscape is healthy when it includes stable populations of native species that are well distributed 

across the landscape. 

Boundaries: The areas that receive protection under the Wild and Scenic Rivers Act. Boundaries 

include an average of not more than 320 acres of land per mile, measured from the ordinary high water 

mark on both sides of the river. 

CEQ Regulations: The Council on Environmental Quality (CEQ) was established by the National 

Environmental Policy Act (see NEPA) and given the responsibility for developing federal 

environmental policy and overseeing the implementation of NEPA by federal agencies. 

Classifications: The status of rivers or river segments under the Wild and Scenic Rivers Act (“wild,” 

“scenic,” or “recreational”). Classification is based on the existing level of access and human alteration 

of the site. 

Comprehensive Management Plan (CMP): A plan to protect and enhance a Wild and Scenic River. 

The Merced River Plan is the National Park Service’s comprehensive management plan for segments 

of the Merced River corridor under its jurisdiction. 

Cultural landscape: A geographic area, including both cultural and natural resources and the wildlife 

or domestic animals therein, associated with a historic event, activity, or person or exhibiting other 

cultural or aesthetic values. There are four general types of cultural landscapes, not mutually exclusive: 

historic sites, historic designed landscapes, historic vernacular landscapes, and ethnographic 

landscapes. 

Ecological restoration: Ecological restoration is the process of assisting the recovery of an ecosystem 

that has been degraded, damaged, or destroyed. 

Emergent wetland: A wetland characterized by frequent or continual inundation dominated by 

herbaceous species of plants typically rooted underwater and emerging into air (e.g., cattails, rushes). 

The emergent wetland class is characterized by erect, rooted, herbaceous hydrophytes (e.g., cattails, 

rushes), excluding mosses and lichens. This vegetation is present for most of the growing season in 

most years. Perennial plants usually dominate these wetlands. All water regimes are included, except 

sub-tidal and irregularly exposed. 
Glossary of Terms 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 12-3

Environmental consequences: This section of an environmental assessment describes the impacts a 

proposed action will have on resources. Direct, indirect, and cumulative impacts, both beneficial and 

adverse, are analyzed. The context, duration, and intensity of impacts are defined and quantified as 

much as possible. 

Environmental Impact Statement (EIS): A public document required under the National 

Environmental Policy Act (NEPA) that identifies and analyzes activities that might affect the human 

and natural environment. 

Environmentally Preferable Alternative: The environmentally preferable alternative is the 

alternative within the range of alternatives presented in a Draft Environmental Impact Statement (EIS) 

that best promotes the goals of the National Environmental Policy Act (NEPA). In general, this is the 

alternative causes the least damage to the environment and best protects natural and cultural 

resources. In practice, one alternative may be more preferable for some environmental resources while 

another alternative may be preferable for other resources. (The NEPA Handbook) 

Ecosystem: An ecosystem can be defined as a geographically identifiable area that encompasses 

unique physical and biological characteristics. It is the sum of the plant community, animal 

community, and environment in a particular region or habitat. 

Erratic: A rock fragment of any size carried by glacial ice, or by floating ice, deposited at some distance 

from the outcrop of origin. 

Facilities: Buildings and the associated supporting infrastructure such as roads, trails, and utilities. 

Floodplain: A nearly level alluvial plain that borders a stream and is subject to flooding unless 

protected artificially. 

Fluvial: Of or pertaining to a river. Fluvial is a technical term used to indicate the presence or 

interaction of a river or stream within the landform. 

Free-flowing river: Existing or flowing in natural condition without impoundment, diversion, 

straightening, riprapping, or other modification of the waterway (as defined in the Wild and Scenic 

Rivers Act - 16 USC 1286 [b]). 

Glacial till: Glacially transported and unconsolidated mixtures of clay, silt, sand, and gravel deposited 

directly by and underneath a glacier without being reworked by melt water. 

Glaciation: Effects on landforms produced by the presence and movement of a glacier. 

Geomorphic: Of or pertaining to the form of the Earth or of its surface features. 

Governing mandates: The National Park Service is directed to address user capacity, resource 

protection, and public enjoyment of park resources through a number of pieces of legislation such as 

laws, regulations, policies, and programs referred to in the Merced River Plan as governing mandates. 

These mandates establish the authority and responsibility for management in Yosemite National Park. 
GLOSSARY AND ACRONYMS

12-4 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Groundwater: All subsurface water (below soil/ground surface), distinct from surface water. 

Groundwater recharge: The process involved in the absorption and addition of surface water to the 

zone of saturation or aquifer. 

Hazardous material: A substance or combination of substances, that, because of quantity, 

concentration, or physical, chemical, or infectious characteristics, may either: (1) cause or significantly 

contribute to an increase in mortality or an increase in serious, irreversible, or incapacitating illness; or 

(2) pose a substantial present or potential hazard to human health or environment when improperly 

treated, stored, transported, disposed of, or otherwise managed. 

Hazardous waste: Hazardous wastes are hazardous materials that no longer have practical use, such 

as substances that have been discarded, spilled, or contaminated, or that are being stored temporarily 

prior to proper disposal. 

Headwaters: The point or area of origin for a river or stream. 

High Sierra Camps: Overnight lodging facilities operated by the concessioner in the wilderness areas 

that include tent cabins, food service, and other amenities. 

Historic building: For the purposes of the National Register of Historic Places, a building can be a 

house, barn, church, hotel, or similar construction, created principally to shelter human activity. 

“Building” may also refer to a historically and functionally related unit, such as a courthouse and jail or 

a house and barn. 

Historic district: A historic district is an area which possesses a significant concentration, linkage, or 

continuity of sites, buildings, structures, or objects united historically or aesthetically by plan or 

physical development. To be eligible for the National Register of Historic Places, a district must be 

significant, as well as being an identifiable entity. It must be important for historical, architectural, 

archeological, engineering, or cultural values. 

Historic property: A historic property is any prehistoric or historic building, site, district, structure, or 

object that is included in, or eligible for inclusion in, the National Register of Historic Places. Types of 

historic properties can include archeological sites, historic cultural landscapes, and traditional cultural 

properties. 

Historic site: A historic site is the location of significant event which can be prehistoric or historic in 

nature. It can represent activities or buildings (standing, ruined, or vanished). It is the location itself 

which is of historical interest in a historic site, and it possesses cultural or archeological value 

regardless of the value of any structures that currently exist on the location. Examples of sites include 

shipwrecks, battlefields, campsites, natural features, and rock shelters. 

Historic structure: For the purposes of the National Register of Historic Places, the term “structure” 

is used to distinguish from buildings those functional constructions made usually for purposes other 

than creating human shelter. Examples of structures include bridges, gazebos, and highways. 
Glossary of Terms 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 12-5

Hydrologic response: The response of a watershed due to precipitation. Usually refers to the 

resulting streamflow from a precipitation event. 

Implementation plan: Implementation plans, which tier off of programmatic plans (like the General 

Management Plan) focus on “how to implement an activity or project needed to achieve a long-term 

goal. Implementation plans may direct specific projects as well as ongoing management activities or 

programs. They provide a more extensive level of detail and analysis than do general management 

plans. Implementation plans are required to undergo NEPA review. 

Implementation project: Implementation projects are specific actions identified in an 

implementation plan. 

Impoundment: A dam or other structure to obstruct the flow of water in a river or stream. 

Lacustrine: Of or relating to lakes. 

Management zone: A geographical area for which management directions or prescriptions have been 

developed to determine what can and cannot occur in terms of resource management, visitor use, 

access, facilities or development, and park operations. 

Metamorphic rock: Metamorphic refers to rocks derived from pre-existing rocks by mineralological, 

chemical, structural changes. 

Mitigation: Activities that will avoid, reduce the severity of, or eliminate an adverse environmental 

impact. 

Native American Graves Protection and Repatriation Act (NAGPRA): The act that requires federal 

agencies and institutions that receive federal funding to return Native American cultural items to their 

respective peoples. This act also establishes a program of federal grants to assist in the repatriation 

process. 

National Environmental Policy Act (NEPA): The federal act that requires the development of an 

environmental impact statement (EIS) for federal actions that might have substantial environmental, 

social, or other impacts. 

National Historic Landmarks (NHL): Are nationally significant historic places designated by the 

Secretary of the Interior because they possess exceptional value or quality in illustrating or interpreting 

the heritage of the United States. 

National Historic Preservation Act (NHPA): In 1966, Congress established a program for the 

preservation of additional historic properties through the country. The NHPA requires federal 

agencies to evaluate the impact of all federally funded or permitted projects on historic properties 

through the Section 106 process. 

National Park Service Organic Act: In 1916, the National Park Service Organic Act established the 

National Park Service in order to “promote and regulate use of parks” and defined the purpose of the 
GLOSSARY AND ACRONYMS

12-6 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

national parks as “to conserve the scenery and natural and historic objects and wild life therein and to 

provide for the enjoyment of the same in a manner and by such means as will leave them unimpaired 

for the enjoyment of future generations.” This law provides overall guidance for the management of 

Yosemite National Park. 

National Parks and Recreation Act: The 1978 law that establishes National Parks, Monuments, 

Recreation Areas and other recreation lands under the jurisdiction of the Department of the Interior. 

This law continues to be amended as new lands are acquired or boundaries of existing lands are 

changed. 

National Register of Historic Places: As a result of the NHPA of 1966, the National Park Service’s 

National Register of Historic Places is part of a national program to coordinate and support public and 

private efforts to identify, evaluate, and protect historic and archeological resources. 

Natural processes: All processes such as hydrologic, geologic, ecosystem that are not the result of 

human manipulation. 

No-Action Alternative: The alternative in a plan that proposes to continue current management 

direction. “No action” means the proposed activity would not take place, and the resulting 

environmental effects from taking no action would be compared with the effects of permitting the 

proposed activity or an alternative activity to go forward. 

Nonattainment Area: A geographical area identified by the U.S. Environmental Protection Agency 

and/or the California Air Resources Board as not meeting national and/or California ambient air 

quality standards (NAAQS / CAAQS) for a given pollutant. Nonnative species: Species of plants or 

wildlife that are not native to a particular area and often interfere with natural biological systems. 

Nonwilderness: Areas that have not been designated for special protection under the Wilderness Act. 

National Park Service Management Policies: A policy is a guiding principle or procedure that sets 

the framework and provides direction for management decisions. National Park Service (NPS) policies 

are guided by and consistent with the Constitution, public laws, Executive proclamations and orders, 

and regulations and directives from higher authorities. Policies translate these sources of guidance into 

cohesive directions. Policy direction may be general or specific. It may prescribe the process by which 

decisions are made, how an action is to be accomplished, or the results to be achieved. The primary 

source of National Park Service policy is the publication Management Policies 2001. The policies 

contained therein are applicable Service-wide. They reflect National Park Service management 

philosophy. Director’s Orders supplement and may amend Management Policies. Unwritten or 

informal “policy” and people’s various understandings of National Park Service traditional practices 

are never relied on as official policy. 

Outstandingly Remarkable Values (ORVs): Those resources in the corridor of a Wild and Scenic 

River that are of special value and warrant protection. ORVs are the “scenic, recreational, geologic, 

fish and wildlife, historic, cultural or other similar values‚ that shall be protected for the benefit and 

enjoyment of present and future generations” (16 USC 1272). 
Glossary of Terms 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 12-7

Overnight capacity: Refers to the actual number of visitors who can be accommodated each night in 

lodging, camping, and wilderness High Sierra Camp facilities within Yosemite National Park. Capacity 

is determined by counting the maximum number of people permitted in each campsite and/or the 

room occupancy within lodging units. 

Palustrine: The palustrine system was developed to group the vegetated wetlands traditionally called 

by such names as marsh, swamp, bog, fen, and prairie, which are found throughout the United States. 

It also includes the small, shallow, permanent, or intermittent waterbodies often called ponds. 

Palustrine wetlands may be situated shoreward of lakes, river channels, or estuaries; on river 

floodplains; in isolated catchments; or on slopes. They may also occur as islands in lakes or rivers. The 

Palustrine system includes all nontidal wetlands dominated by trees, shrubs, persistent emergents, 

emergent mosses or lichens, and all such wetlands that occur in tidal areas where salinity due to oceanderived salts is below 0.5%. It also includes wetlands lacking such vegetation, but with all of the 

following four characteristics: (1) area less than 8 hectares (20 acres); (2) active wave-formed or 

bedrock shoreline features lacking; (3) water depth in the deepest part of basin less than 2 meters at 

low water; and (4) salinity due to ocean-derived salts less than 0.5%. 

Particulate matter (PM-10 and PM-2.5): Fractions of particulate matter characterized by particles 

with diameters of 10 microns or less (PM-10) or 2.5 microns or less (PM-2.5). Such particles can be 

inhaled into the air passages and the lungs and can cause adverse health effects. High levels of PM-2.5 

are also associated with regional haze and visibility impairment. 

Planning: A dynamic, interdisciplinary, process for developing short- and long-term goals for visitor 

experience, resource conditions and facility placement. 

Pluton: A general term applied to any body of intrusive igneous rock that originates deep in the earth. 

Named for Pluto, Greek god of the underworld. 

Potential wilderness additions: Areas in wilderness where an existing use precluded full designation 

under the California Wilderness Act. 

Preferred Alternative: The preferred alternative is the alternative within the range of alternatives 

presented in a Draft Environmental Impact Statement (EIS) that the agency believes would best fulfill 

the purpose and need of the proposed action. While the preferred alternative is a different concept 

from the environmentally preferable alternative, they may also be one and the same for some EISs. 

(The NEPA Handbook) 

Pristine: Unaltered, unpolluted by humans. 

Programmatic plan: Programmatic plans establish broad management direction for Yosemite 

National Park. The 1980 General Management Plan it a programmatic plan with a purpose to set a 

“clearly defined direction for resource preservation and visitor use” and provide general directions 

and policies to guide planning and management in the park. The Merced River Plan is also a 

programmatic plan that guides future activities in the Merced River corridor. Programmatic plans are 

required to undergo NEPA review. 
GLOSSARY AND ACRONYMS

12-8 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Public comment process: The public comment process is a formalized process required by the 

National Environmental Policy Act (NEPA) in which the National Park Service must publish a Notice 

Of Availability in the Federal Register which provides public notice that a Draft Environmental Impact 

Statement (EIS) and associated information, including scoping comments and supporting 

documentation, is available for public review and input pursuant to the Freedom Of Information Act. 

In addition, the National Park Service must conduct formal public hearings on the Draft EIS when 

required by statute or the Council on Environmental Quality NEPA Regulations. 

Public scoping process: Scoping is a formalized process used by the National Park Service to gather 

the public’s and other agencies’ ideas and concerns on a proposed action or project. A Notice Of 

Intent (NOI) is published in the Federal Register announcing the agency’s intent to prepare an 

Environmental Impact Statement and a request for written public/other agency scoping comments to 

further define the goals and data needs for the project. In addition, although not required by the 

National Environmental Policy Act (NEPA) nor the Council on Environmental Quality (CEQ) NEPA 

Regulations, public scoping meetings may be held and integrated with any other early planning 

meetings relating to the proposed project. 

Record of Decision: The public document describing the decision made on selecting the “preferred 

alternative” in an environmental impact statement. See “environmental impact statement.” 

Riffle (riffle/pool): A riffle is part of the natural sequence of a stream pattern as it alters between 

riffles and pools in the linear direction. Riffles are the steeper, shallower areas where turbulence is 

usually present due to shallow water flowing over the channel substrate. Pools are the calmer, less 

steep areas where deeper water is present, typically in a wider channel width. Additionally, there are 

glides that are linear stream areas where no turbulence is present due to sufficiently deep water but 

stream velocities are higher than typical of pool areas. Glides are usually not as wide across the stream 

channel as compared to pools. 

Riparian areas: The land area and associated vegetation bordering a stream or river. 

Riprap: A layer of large, durable fragments of broken rocks specially selected and graded, thrown 

together irregularly or fitted together to prevent erosion by waves or currents. 

Riverine: Of or relating to a river. A riverine system includes all wetlands and deepwater habitats 

contained within a channel, with two exceptions: (1) wetlands dominated by trees, shrubs, persistent 

emergents, emergent mosses, or lichens, and (2) habitats with water containing ocean-derived salts in 

excess of 0.5%. A channel is an open conduit either naturally or artificially created which periodically 

or continuously contains moving water, or which forms a connecting link between two bodies of 

standing water. 

River corridor: The area within the boundaries of a wild and scenic river (e.g., the Merced River 

corridor). 

Section 7 determination process: Section 7 of the Wild and Scenic Rivers Act specifies restrictions on 

hydro and water resources development projects. Water resources projects are subject to Section 7 of 

the Wild Scenic Rivers Act (16 USC 1278). Section 7(a) states, “no department or agency of the United 
Glossary of Terms 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 12-9

States shall assist by loan, grant, license or otherwise in the construction of any water resources project 

that would have a direct and adverse effect on the values for which such river was established, as 

determined by the Secretary charged with its administration.” 

Sediment: A particle of soil or rock that was dislodged, entrained, and deposited by surface runoff or a 

stream. The particle can range in size from microscopic to cobble stones. 

Segment: Section 2 of the Wild and Scenic Rivers Act requires that the Merced River be classified and 

administered as “wild”, “scenic”, or “recreational” river segments, based on the condition of the river 

corridor at the time of boundary designation. The classification of a river segment indicates the level of 

development on the shorelines, the level of development in the watershed, and the accessibility by 

road or trail. “Wild” segments are free of impoundments and generally inaccessible except by trail, 

with watersheds and/or shorelines essentially primitive and unpolluted; “Scenic” segments are free of 

impoundments, with watersheds and shorelines largely undeveloped, but accessible in places by roads; 

and, “Recreational” segments are readily accessible by road or railroad, may have some development 

along the shorelines, and may have undergone impoundment or diversion in the past. There are no 

segments classified as ‘recreational’ in the Merced River corridor. 

Site hardening: Any development that creates an impervious ground surface. Usually used as a way to 

direct visitor use and reduce impacts to resources. 

Social trails: A social trail is an informal, nondesignated trail between two locations. Social trails often 

result in trampling stresses to sensitive vegetation types. 

Special Status Species: Species of plants and animals that receive special protection under state 

and/or federal laws. Also referred to as “listed species” or “endangered species.” 

Subalpine: Designating or growing in mountain regions just below the timberline. 

Superintendent’s Compendium: Under the authority of 16 U.S.C., Section 3, and Title 36 Code of 

Federal Regulations, Chapter 1, Parts 1-7; the Compendium of Superintendent’s Orders was 

established for Yosemite National Park, referred to as the “Superintendent’s Compendium” in the 

Revised Merced River Plan/SEIS. Each park superintendent has discretionary authority to regulate or 

limit certain uses, and/or require permits for specific activities within the boundaries of a national 

park. (See II-9 for text version of definition) 

Traditional cultural resource: Any site, structure, object, landscape, or natural resource feature 

assigned traditional, legendary, religious, subsistence, or other significance in the cultural system of a 

group traditionally associated with it. 

Traditional cultural property: Traditional cultural resource that is eligible for or listed on the 

National Register of Historic Places as a historic property. 

Treatment: Work carried out to achieve a historic preservation goal. The four primary treatments are 

preservation, rehabilitation, restoration, and reconstruction (as stated in the Secretary of the Interior’s 

Standards for the Treatment of Historic Properties). 
GLOSSARY AND ACRONYMS

12-10 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

User capacity: As it applies to parks, user capacity is the type and level of use that can be 

accommodated while sustaining the desired resource and social conditions based on the purpose and 

objectives of a park unit. 

User: Visitors and employees in the Merced River corridor. 

Visitor experience: The perceptions, feelings, and reactions a park visitor has in relationship with the 

surrounding environment. 

Visitor use: Refers to the types of recreation activities visitors participate in, numbers of people in an 

area, their behavior, the timing of use, and distribution of use within a given area. 

Visitor use levels: Refers to the quantity or amount of use a specific area receives, or the amount of 

parkwide visitation on a daily, monthly or annual basis. 

Walk-in campground: A campground with consolidated parking areas separated from the individual 

campsites. Campers walk a short distance from the parking area to their campsites. 

Watershed: The region drained by, or contributing water to, a stream, lake, or other body of water. 

Synonym: basin or drainage basin. 

Wetland: Wetlands are defined by the U.S. Army Corps of Engineers (CFR, Section 328.3[b], 1986) as 

those areas that are inundated or saturated by surface or ground water at a frequency and duration 

sufficient to support, and that under normal circumstances do support, a prevalence of vegetation 

typically adapted for life in saturated soil conditions. 

Wild and Scenic River: A river receiving special protection under the Wild and Scenic Rivers Act. 

Wilderness: Designated wilderness areas are protected by the provisions of the 1964 Wilderness Act; 

they are characterized by a lack of human interference in natural processes. 

Wilderness Act of 1964: The Wilderness Act restricts development and activities to maintain certain 

places where wilderness conditions predominate. 

Wilderness Impact Monitoring System (WIMS): Wilderness monitoring is an integral part of 

Yosemite’s wilderness management program. Visitor use patterns have been tracked since 1975 from 

wilderness permits and field reports by rangers. Monitoring of campsite and trail impacts began in the 

1970s. A program now called the Wilderness Impact Monitoring System (WIMS) monitors and 

evaluates campsite conditions in the wilderness that ensure that the trailhead quotas and wilderness 

education about proper backcountry care are adequately protecting wilderness values. Using WIMS, 

visitor satisfaction information, patrol data, and a variety of other studies, the National Park Service 

conducts wilderness-wide inventory and monitoring. Data gathered from these studies are used to 

determine when, where, and why significant change occurs, to adjust management practices as 

appropriate to eliminate unacceptable impacts, and to provide a system for tracking those changes. 
Acronyms and Abbreviations 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 12-11

Wilderness Trailhead Quota System: The Wilderness Trailhead Quota System was established in the 

1970s to protect wilderness areas within Yosemite National Park. This system assigns a daily quota for 

each wilderness trailhead in the park. The quotas are based on scientific studies that evaluated ecological 

condition and historic use patterns. Controlling use at the trailhead allows for maximum visitor freedom-

-considered a cornerstone in wilderness experience--while allowing the park to limit or disperse use as 

appropriate. The Wilderness Trailhead Quota System allows for a total of 1,280 overnight visitors to 

enter the wilderness each day. Day use in Wilderness is not currently limited or controlled. 

ACRONYMS AND ABBREVIATIONS 

ACHP Advisory Council on Historic Preservation 

ADA The Americans with Disabilities Act 

AIRFA American Indian Religious Freedom Act 

ARPA Archaeological Resources Protection Act 

CAAQS California Ambient Air Quality Standards 

CARB California Environmental Protection Agency, Air Resources Board 

CCC Civilian Conservation Corps 

CDFG California Department of Fish and Game 

CDN Communications Data Network 

CEQ Council on Environmental Quality 

CFR Code of Federal Regulations 

cfs cubic feet per second 

CMP Comprehensive Management Plan 

DCS Distributed control subsystem 

dB Decibel 

dBA Decibel (on the “A-weighted” scale) 

DNC Delaware North Companies Parks and Resorts at Yosemite, Inc. 

DO Director’s Order 

EA Environmental assessment 

EIS Environmental impact statement 

EPA U.S. Environmental Protection Agency 

FEIS Final environmental impact statement 

FONSI Finding of No Significant Impact 

GIS Geographic information system(s) 

GMP General Management Plan 

gpd Gallons per day 

gpm Gallons per minute 

IWSRCC Interagency Wild and Scenic Rivers Coordinating Council 

kWh Kilowatt hour 

NAAQS National Ambient Air Quality Standards 

NAGPRA Native American Graves Protection and Repatriation Act 

NEPA National Environmental Policy Act 
GLOSSARY AND ACRONYMS

12-12 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

NHPA National Historic Preservation Act 

NPS National Park Service 

NRCS National Resources Conservation Service 

NRHP National Register of Historic Places 

NPS National Park Service 

NWI National Wetlands Inventory 

ORV Outstandingly Remarkable Value 

PEPC Planning, Environment, and Public Comment 

PG&E Pacific Gas and Electric 

PM Particulate matter 

RWQCB Regional Water Quality Control Board 

RV Recreational Vehicle 

SHPO State Historic Preservation Officer 

SNEP Sierra Nevada Ecosystem Project 

UFAS Uniform Federal Accessibility Standards 

USACE U.S. Army Corps of Engineers 

USFS United States Forest Service 

USFWS United States Fish and Wildlife Service 

USGS United States Geological Survey 

VOC Volatile Organic Compound 

WIMS Wilderness Impact Monitoring System 

YARTS Yosemite Area Regional Transportation System 

YCC Youth Conservation Corps 

YTS Yosemite Transit System