Analysis Topics: Natural Resources 

Vegetation and Wetlands 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-183

Vegetation and Wetlands 

Affected Environment 

Regulatory Framework

Vegetation 

NPS Management Policies (2006) establishes Service-wide vegetation management policy. These 

policies state, “Whenever possible, natural processes will be relied upon to maintain native plant and 

animal species and influence natural fluctuations in populations of these species.” The 1997 Vegetation 

Management Plan (NPS) provides broad guidance and specific implementation plans for vegetation 

management in Yosemite. Specific statuary directives that influence vegetation management in 

Yosemite include Executive Order No. 13112 - Invasive Species. The 2008 Yosemite Invasive Plant 

Management Plan and its 2010 Update (NPS) and the Fire Management Plan for Yosemite National 

Park (NPS 2004b) are park-specific plans play a large part in protecting the integrity of vegetation in 

Yosemite. The Merced River Plan/DEIS defers to these plans in most cases to provide a framework for 

invasive plant management efforts and supports the use of fire to shape the ecosystems of the park. 

Wetlands 

The NPS will manage wetlands in compliance with NPS mandates and the requirements of the Clean 

Water Act (CWA), the Rivers and Harbors Appropriation Act of 1899 (Rivers and Harbors Act), 

Executive Order 11990 (“Protection of Wetlands”), the procedures described in Director’s Order 77-1 

(“Wetland Protection”), and its accompanying Procedural Manual #77-1 (NPS 2008). Executive Order 

11990 directs the NPS to (1) provide leadership and take action to prevent the destruction, loss, or 

degradation of wetlands; (2) preserve and enhance the natural and beneficial values of wetlands; and 

(3) avoid direct and indirect support of new construction in wetlands unless there are no practicable 

alternatives and the proposed action includes all practicable measures to minimize harm to wetlands. 

Any actions that may reduce or degrade wetlands are governed by the CWA and Rivers and Harbors Act, 

and regulated by the U.S. Army of Corps of Engineers (Corps) and the U.S. Environmental Protection 

Agency. The NPS will implement a “no net loss of wetlands” policy (NPS 2006, section 4.6.5). 

Clean Water Act. The CWA requires the NPS to comply with all federal, state, interstate, and local 

requirements to control and abate water pollution. CWA section 404 regulates the discharge of 

dredged and fill materials into waters of the United States. Waters of the United States refers to oceans, 

bays, rivers, streams, lakes, ponds, and wetlands. Applicants must obtain a permit from the Corps for all 

discharges of dredged or fill material into waters of the United States, including wetlands, before 

proceeding with a proposed activity. Under CWA section 401, all projects that have a federal 

component and may affect state water quality (including projects that require federal agency approval, 

such as issuance of a section 404 permit) must also comply with CWA section 401. 

Rivers and Harbors Act of 1899. Section 10 of the Rivers and Harbors Act prohibits the unauthorized 

obstruction or alteration of any navigable water of the United States. The act regulates construction of 

any structure in or over any navigable water. This includes any work that might affect the course, 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-184 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

location, condition, or physical capacity of such waters. Work must be recommended by the Chief of 

Engineers and authorized by the Secretary of the Army. 

Executive Order 11990. “Protection of Wetlands” establishes the protection of wetlands and riparian 

systems as the official policy of the federal government. It requires all federal agencies to consider 

wetland protection as an important part of their policies and take action to minimize the destruction, 

loss or degradation of wetlands, and to preserve and enhance the natural and beneficial values of 

wetlands. A Wetland Statement of Findings is prepared if adverse impacts on wetlands are identified. 

The Wetland Statement of Findings for the Merced River Plan/DEIS is included as Appendix O. The 

NPS Director’s Order #77-1 (“Wetland Protection”) gives implementation detail to Executive 

Order 11990. 

Regional Vegetation 

The major vegetation zones of the Sierra Nevada region form readily apparent, large-scale, northsouth elevational bands along the axis of the Sierra Nevada range. In the Yosemite region, these 

vegetation zones include foothill-woodland, lower montane forest, upper montane forest, subalpine 

forest, and alpine zones; they are distributed from the lowest elevations on the western boundary of 

the park to the highest elevations along the crest of the Sierra Nevada range. Major east-west 

watersheds that dissect the Sierra Nevada range into steep canyons form a secondary pattern of 

vegetation. 

A parkwide vegetation map — the first vegetation map of Yosemite since the 1930s — was created over 

a 10-year period, from 1997 to 2007. It combines detailed data from 1,500 aerial photographs and 

hundreds of field surveys to provide information on floristic classification. The map identifies 129 

distinct vegetation classes, which are grouped into eight broad vegetation types. This map was used to 

determine the broad vegetation types that occur within the Merced River corridor. The broad 

vegetation types are discussed in more detail below. 

Merced River Vegetation 

As discussed above, Yosemite National Park supports eight major vegetation types, all of which occur 

within the Merced River corridor and are discussed below and presented in table 9-2 and figure 9-7. 

Within these eight broad vegetation types, the parkwide vegetation map includes 129 distinct 

vegetation classes. The following narrative provides a general description of vegetation types within 

1.5 miles of the Merced River (study area). Descriptions of plant communities, including distribution 

limits, habitat requirements, community sensitivities, and a list of plant species characteristically found 

in conjunction with each plant assemblage appear in the Vegetation Management Plan (NPS 1997c), the 

Parkwide Vegetation Map (NPS 2007), the Merced River and Riparian Vegetation Assessment (Cardno 

ENTRIX 2011), and the 2010 Assessment of Meadows in the Merced River Corridor, Yosemite National 

Park (Ballenger et al. 2011). 
Analysis Topics: Natural Resources 

Vegetation and Wetlands 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-185

TABLE 9-2: MAJOR VEGETATION TYPES IN THE MERCED RIVER CORRIDOR

Vegetation Type 

Area per Segment (acres) 

1 2 3 4 5 6 7 8 Total 

Alpine (9,500 to 

11,800 feet)* 87.8 0 0 0 6.5 0 0 0 94.3 

Meadow (2,000 to 

11,000) 1,801.3 324.1 67.6 28.8 389.0 0 140.6 0.9 2,752.3 

Chaparral (2,000 to 

10,000 feet) 1,669.1 991.4 2,270.6 74.9 694.0 0 166.4 66.6 5,933.0 

Subalpine Coniferous 

Forest (8,000 to 

9,500 feet) 

9,610.4 45.8 0 0 3,108.9 0 0 0 12765.1 

Upper Montane 

Coniferous Forest 

(6,000 to 8,000 feet) 

16,525.7 3,697.0 1,572.0 0 11,611.8 23.3 990.5 28.4 34,448.7

Lower Montane 

Coniferous Forest 

(3,000 to 6,000 feet) 

3,505.6 7,248.5 4,785.3 151.4 6,010.4 72.0 4,969.0 1,980.8 28,723.0

Lower Montane 

Broadleaf Forest 

(3,000 to 6,000 feet) 

461.6 3,331.4 2,982.7 569.7 816.7 3.4 761.1 397.0 9,323.6 

Foothill Woodland 

(1,800 to 3,000 feet) 0 0 9.8 324.8 0 0 0 0 334.6 

Barren (1,800 to 

11,800 feet) 14,143.4 2,319.5 455.7 27.6 2586.4 2.9 170.2 2.6 19,708.3

Developed 0.3 150.0 59.3 54.5 8.1 0.2 82.2 10.3 364.9 

*Elevation ranges are approximated 

SOURCE: NPS 1997; NPS 2007 

Merced River Wetlands and Riparian Habitats 

Wetlands and riparian areas are distinct habitats that provide a variety of hydrologic and ecological 

functions vital to ecosystem integrity. These functions include flood abatement, sediment retention, 

groundwater recharge, nutrient capture, and support of high levels of plant and animal diversity. Many 

riparian areas are classified as wetlands. Wetlands and riparian areas are relatively rare compared with 

the entire landscape. Modification of even small wetland areas can induce effects that are 

proportionally greater than elsewhere in an ecosystem due to the ecological importance of wetlands. 

Wetlands receive special protection under Executive Order 11990 (“Protection of Wetlands”), and 

section 404 of the CWA. 

The NPS parkwide vegetation map classifies some riparian communities; however riparian and 

wetland areas are not classified independently under the eight broad-scale vegetation types used in the 

parkwide vegetation map, and the minimum mapping unit is too large to capture many riparian areas 

and wetlands. For the purposes of this document, the NPS used additional data to quantify and 

describe wetlands and riparian habitat. Wetland data were obtained from site-specific wetland 

delineations for limited areas in Yosemite Valley. National Wetland Inventory data (USFWS 1995), 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-186 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

supplemented with data from the Yosemite Parkwide Vegetation Map (1997), were used to describe 

wetlands in the Merced River corridor in areas where delineation data were not available (site-specific 

wetland delineation data was only available for limited areas in Yosemite Valley). Data on riparian 

habitats was obtained from the Merced River and Riparian Vegetation Assessment (Cardno ENTRIX 

2011) for the river corridor through Yosemite Valley. Data from the Yosemite Parkwide Vegetation Map 

(1997) were used to describe riparian habitats outside of Yosemite Valley. 

Wetland and riparian habitat data presented in this section are descriptive, including actual extent 

(location on the ground and acreage) for each segment of the Merced corridor within Yosemite 

National Park. This provides an overview of the types of wetlands and riparian habitats that occur 

across the study area. The intent is to provide general descriptions, functions, and values of wetland 

and water-dependent communities within the study area. 

Wetland Classification and Definition 

The NPS standard for identifying wetlands is a system developed by wetland ecologists and an 

interagency team for the U.S. Fish and Wildlife Service (USFWS) referred to as the Cowardin 

classification system (Cowardin et al. 1979). Wetlands, as defined by the USFWS, are transitional lands 

between terrestrial and aquatic systems where the water table is usually at or near the surface, or the 

land is covered by shallow water (Cowardin et al. 1979). For purposes of this classification, wetlands 

must have one or more of the following attributes: 

 The land predominantly supports hydrophytes, at least periodically. Hydrophytes are 

plants that grow in water or on a substrate that is at least periodically deficient in oxygen 

as a result of excessive water content. 

 The substrate is predominantly undrained hydric soils. Hydric soils are wet long enough 

to periodically produce anaerobic conditions. 

 The substrate is saturated with water or covered by shallow water at some time during the 

growing season of each year (Cowardin et al. 1979). 

The Corps uses three wetland parameters to define wetlands for regulatory purposes: hydrophytic 

vegetation, hydric soil, and wetland hydrology. When all three parameters are present, the wetland is 

considered a jurisdictional wetland. The Cowardin system defines more habitat types as wetlands than 

does the Corps definition as it recognizes some unvegetated sites (e.g., mudflats, stream shallows, 

saline lakeshores, playas) or sites lacking soil (e.g., rocky shores, gravel beaches) as wetland habitats if 

wetland hydrology is present. The reason these sites lack hydrophytic vegetation and/or hydric soil is 

due to natural chemical or physical factors. Although the Corps does not consider these sites to be 

wetlands, they are still subject to regulations under section 404 of the CWA as other waters of the 

United States. For purposes of this document, both Cowardin wetlands and waters of the United 

States as defined by the Corps are referred to as wetlands. 
M a d e r a C o u n t y

South Fork Me rced River

Merced River

M a r i p o s a C o u n t y

River Segment 4.

El Portal

River Segment 2.

Yosemite Valley River Segment 1. Merced R

Above Nevad

River Segment 5.

South Fork

Merced River

Above Wawona

River Segment 6.

Wawona Impoundment

River Segment 8.

South Fork

Merced River

Below Wawona

River Segment 7.

Wawona

River Segment 3.

Merced Gorge

County Boundary

Study Area

Yosemite National Park

River Corridor

Vegetation

Alpine

Barren

Chaparral

Foothill Woodland

Lower Montane Broadleaf

Lower Montane Needleleaf

Meadow

Subalpine Needleleaf

Upper Montane Needleleaf

Water

SOURCE: NPS, 1997, 2011
THIS PAGE INTENTIONALLY LEFT BLANK 
Analysis Topics: Natural Resources 

Vegetation and Wetlands 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-189

Specific wetland classes identified within the river corridor include riverine (rivers, creeks, and 

streams), palustrine (shallow ponds, riparian wetlands, wet meadows, marshes), and lacustrine (lakes 

and ponds). Using the Cowardin classification system, specific wetlands and deepwater classes within 

the Merced River corridor consist of the following subclasses: 

 Riverine upper perennial — main channels of the Merced River and the South Fork Merced 

River (may be wetland or deepwater habitat depending on depth) 

 Riverine intermittent — intermittent tributaries to the Merced River and South Fork Merced 

River (wetlands) 

 Palustrine emergent — emergent wetland habitat (marsh, meadow) along the Merced River 

and South Fork Merced River subject to various flooding regimes 

 Palustrine forested — riparian forest wetland habitat along the Merced River and South Fork 

Merced River subject to various flooding regimes 

 Palustrine scrub shrub — riparian scrub (e.g., willow) wetland habitat along the Merced River 

and South Fork Merced River and its tributaries subject to various flooding regimes 

 Lacustrine littoral – shallow lake margins that are less than 2 meters deep at low water and have 

less than 30% vegetation cover 

 Lacustrine limnetic — portions of lakes that are more than 2 meters deep at low water (e.g., 

Merced Lake, Washburn Lake) along the Merced River (deepwater habitat) 

The following discussion provides general descriptions for each wetland class identified within the 

Merced River ecosystem. 

Riverine Upper Perennial. Riverine upper perennial habitat within the corridor includes the open 

and flowing water of the Merced River and the South Fork Merced River. It is the permanently 

flooded rock-, cobble-, or sand-bottom channel with little to no in-stream vegetation. Occasional 

sandbars form within and at the channel edge and typically support willows and emergent (grasses and 

herbs) vegetation. Based on the NPS guidelines, the majority of the main stem of the Merced River and 

the South Fork Merced River would be classified as riverine upper perennial wetland. Channel portions 

that lie at a depth of 2 meters below low water would be considered deep water. The main channel of the 

Merced River and the South Fork Merced River would likely be considered as jurisdictional by the 

Corps under section 404 of the CWA, not as wetlands but as other waters of the United States. 

Riverine Intermittent. Numerous riverine intermittent drainages (other waters of the United States) are 

tributaries to the main stem Merced River and the South Fork Merced River. Almost all riverine 

intermittent drainages within the river corridor are classified as Cowardin wetlands and waters of the 

United States. These drainages often have a nonsoil substrate that is saturated and/or covered by shallow 

water at some time during the growing season. These wetlands are typically narrow and encompass the 

lowest portion of creekbeds. Very little wetland vegetation is found in these areas because of the 

intermittent nature of the flows within the drainage channels. All aboveground drainages within the river 

corridor are subject to the NPS protection policies under Executive Order 11990. These drainages are 

classified as other waters of the United States and would be subject to sections 401 and 404 of the CWA. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-190 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Palustrine Emergent. Palustrine emergent wetland habitat includes portions of alpine, subalpine, and 

montane meadows1 and seeps. These wetland soils are generally deep and peaty, remaining saturated 

year-round or on a seasonal basis. Vegetation is dominated by grasses, sedges, rushes, and perennial 

herbs. The meadow wetlands in Yosemite National Park play a particularly critical role in the Merced 

River ecosystem. High spring flows create wet areas in side channels, low-lying wetlands, meadows, and 

cutoff channels. These areas support the concentration of organic matter, nutrients, microorganisms, 

and aquatic invertebrates throughout the relatively dry summer. When the flush of winter or spring 

flooding occurs, this stored aquatic biomass is washed into the main river channel, forming the base of 

the aquatic food chain. Examples of palustrine wetlands include portions of Cook’s Meadow and 

meadows adjacent to Washburn and Merced Lakes. These meadow portions are considered wetlands 

under the Cowardin system, and portions of meadows may also meet the Corps’ wetland criteria. 

Delineated palustrine emergent wetlands are subject to the NPS protection policies under Executive 

Order 11990 and section 404 of the CWA. 

Palustrine Forested. Palustrine forested wetlands are the riparian forest habitats along the main stem 

of the Merced River and South Fork Merced River that are regularly inundated by normal high-water 

or flood flows. Palustrine forests within the upper reaches of the main stem of the Merced River and 

South Fork Merced River consist mainly of evergreen pines and firs, with occasional aspens. In 

Yosemite Valley, where the river is broad, shallow, and slow-moving, deciduous cottonwoods, 

willows, and alders dominate the riparian corridor. Substrate under the palustrine forest community 

varies from rock, gravel, sand, clays, loams, and mud. These areas are classified as either wetland or 

other waters of the United States by the Corps, depending on site-specific vegetation, soils, and 

hydrologic conditions, and would be subject to section 401 and/or 404 of the CWA. 

Palustrine Scrub Shrub. This habitat type occurs sporadically along the banks of the main stem of the 

Merced River, the South Fork Merced River, and at lake margins. It is regularly inundated by normal 

high-water or flood flows. This habitat is dominated by various willows and often intergrades with 

meadow (palustrine emergent) and riparian (palustrine forest) communities. These communities are 

typically considered wetlands under the Cowardin system, would be subject to the NPS protection 

policies under Executive Order 11990, and typically meet the Corps’ wetland criteria. These areas may 

meet the Corps’ criteria of a wetland or other waters of the United States, depending on site-specific 

vegetation, soils, and hydrologic conditions, and may be subject to sections 401 and/or 404 of the CWA. 

Lacustrine Littoral. Lacustrine littoral includes all wetland habitats within a lacustrine system. This 

classification extends from the shoreward boundary of the system to a depth of 2 meters below low 

water or to the maximum extent of emergent vegetation. These habitats are adjacent to deep-water 

lakes and reservoirs along the Merced River. These communities are typically considered wetlands 

under the Cowardin system, would be subject to the NPS protection policies under Executive Order 

11990, and may meet the Corps’ wetland criteria, depending on site-specific vegetation, soils, and 

hydrologic conditions, and may be subject to sections 401 and/or 404 of the CWA. 

Lacustrine Limnetic. Lacustrine limnetic refers to deepwater lakes and reservoirs, such as Merced 

and Washburn lakes. Both lakes were formed along the Merced River by glacial activity. In-lake 

 

1 As discussed in this section, the term “meadow” can refer to both upland meadows and wetland meadows. When 

specifically discussing wetland meadows, the wetland nature of the meadow will be indicated. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-191

vegetation is typically limited to rooted aquatic grasses, floating vascular plants, and algae. Meadow 

(palustrine emergent) and riparian (palustrine forest and palustrine scrub shrub) communities 

generally border lake margins. 

These lakes provide important habitat for fish, amphibians, reptiles, and other aquatic species. Substrate 

varies from rock, gravel, sand, and mud. Lacustrine limnetic (deepwater lakes and ponds) are classified as 

deepwater habitat based on the Cowardin system (USFWS 1995). These areas are typically classified as 

other waters of the United States by the Corps and would be subject to regulation under section 404 of 

the CWA. 

Areal Extent of Wetland and Riparian Habitats 

There are wetlands and/or riparian habitats in every segment of the Merced River corridor. The 

classes and extent of wetlands and riparian habitats are summarized in table 9-3. In order to provide 

clarity to the discussion on wetlands and riparian habitats under the “Environmental Consequences” 

section below, the six Cowardin classes were consolidated into two broader classes (“Wetlands” and 

“Riparian Habitats”). 

TABLE 9-3: CLASSES AND AREAL EXTENT OF WETLANDS AND RIPARIAN HABITATS IN THE MERCED RIVER CORRIDOR

Wetland/Riparian Class Area per Segment (acres) 

Name Cowardin Class 1 2 3 4 5 6 7 8 

Wetlands 

Riverine/Lacustrine 404.5 141.0 96.2 42.3 89.5 0.4 64.0 27.7 

Palustrine Emergent 

Wetland (wet meadows) 216.5 261.2 0 1.7 69.8 0 0 0 

Riparian 

Habitats 

Palustrine Forested 

Wetland 0 116.7 11.8 5.2 0.9 0 0 0 

Palustrine Scrub Shrub 

Wetland 10.0 13.7 12.0 4.6 3.3 0 2.5 0 

SOURCE: USFWS 1995; NPS 1997; NPS 2011 

Vegetation 

Segment 1: Merced River Above Nevada Fall 

At its headwaters, the Merced River begins in the lower alpine/subalpine forest zone. The river then 

descends through the upper montane forest zone and flows through Little Yosemite Valley within the 

lower montane forest zone. Vegetation in the upper main stem river corridor is classified into seven 

broad vegetation types: meadow, chaparral, lower montane broadleaf forest, lower montane coniferous 

forest, upper montane coniferous forest, subalpine coniferous forest, and alpine plant communities. 

There are also areas categorized as barren, which include talus and scree slopes, permanents snowfields, 

boulder fields, and other unvegetated areas. Segment 1 of the river is designated as Wilderness. Along 

many segments of the upper Merced River corridor, the river is bordered by a narrow riparian zone, and 

small wetlands occur throughout Segment 1. As mentioned above (see Merced River Wetlands and 

Riparian Habitats), riparian and wetland areas are not classified independently under the eight broad 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-192 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

vegetation types used in the parkwide vegetation map. These habitats are discussed in depth in the 

“Wetland and Riparian Habitats” subsection below. 

Meadow Plant Communities. Numerous small meadows and adjacent riparian habitat are present in 

the upper reaches of the Merced River corridor above Nevada Fall (NPS 1997c, figures 9-8 and 9-9). 

These high-elevation meadows (above 7,000 feet) can be subdivided into alpine meadows (above 

9,600 feet) and subalpine meadows (7,000 to 9,600 feet). Subalpine and alpine meadows are further 

subdivided into wet and dry types with both types sometimes occurring in the same meadow. Highelevation meadows within Segment 1 are considered a key element of the river’s biological ORV. 

Alpine meadows form thin margins around small glacial lakes and are generally steeper, rockier, and 

support sparser and shorter vegetation than lower elevation meadows. Alpine meadows exhibited less 

conifer encroachment, no presence of non-native species, and little to no impacts from visitor use or 

pack stock. Formal NPS trails run through some alpine meadows in the Red Peak and Triple Peak 

Forks and exhibit trail braiding and rutting (Ballenger et al. 2011). 

In many areas (for example, the margins of Merced and Washburn Lakes), subalpine meadows form a 

transition zone from the aquatic environment to drier coniferous forests. At these elevations (7,000 to 

9,600 feet), larger meadow complexes are infrequent but are present in some locations. A large 

meadow plant community occurs within Echo Valley. These wetland plant communities are 

hydrologically driven by the groundwater and flooding regime of the Merced River (NPS 1997; 

Ballenger et al. 2011; Sawyer et al. 2009). 

Although human presence in these areas now designated as wilderness has been ongoing for 

thousands of years, the upper reaches of the Merced River and its associated riparian and wetland 

communities remain intact and relatively free from disturbance. Although subalpine meadows 

historically experienced grazing impacts, most of the meadows in Segment 1 have not been grazed for 

several decades. The meadows at Merced Lake were grazed by NPS and concessioner stock until 1987, 

and they showed typical grazing-related impacts such as trampling, erosion, and a decline in herbaceous 

production when documented in 1961 (Sharsmith). Meadows in this area were closed to stock in the 

1990s, with the exception of Merced Lake East Meadow, which currently serves as a holding area for 

NPS stock. This meadow has the highest levels of pack stock use in terms of vegetation and bare ground 

of any meadow in the corridor. The vegetation in Merced Lake-West and Merced Lake-Shore meadows 

appears to have recovered since these meadows were closed to grazing (Ballenger et al. 2012). 

The recently completed 2010 Assessment of Meadows in the Merced River Corridor, Yosemite National 

Park (Ballenger et al. 2011) provides detail on the current condition of meadow habitats in the Merced 

River corridor in Yosemite National Park. The authors found that subalpine meadows in the Merced 

River corridor are dominated by native graminoids,2 a potentially healthy sign of meadow integrity 

because these species create dense sods that stabilize soils. Subalpine meadows in the Red Peak Fork 

and Triple Peak Fork have a relatively higher proportion of subshrubs and forbs. Bladder sedge (Carex 

utriculata and C. vesicaria) communities dominate most subalpine zone meadows in the Little 

Yosemite, Merced Lake, Doc Moyle’s, and Washburn Lake meadows. The dominance of these 

 

2 Graminoids are grasses and grass-like plants, and include plants in the Poaceae (grasses), Cyperaceae (sedges), and 

Juncaceae (rushes) families. 
Washburn

Lake

Harriet

Lake

Edna

Lake

Merced River Watershed

South Fork

Merced River Watershed

Washburn

Stock Camp

Doc Moyle's

Stock Camp Lyell Fo

e M cr de eP

ak oF

kr Merc de i R ev r

Red Peak Fo kr e M cr ed R vi er

Triple PeakFork Merced

River

Washburn

Lake Meadow

Doc Moyle's

Meadow- West Doc Moyle's

Meadow- East

Triple Peak

Meadow- South

Triple Peak

Meadow- North

Red Peak

Meadow- South

Red Peak

Meadow- North

Turner

Meadow- South

sI eb

gr aP ss

none

r G Py a ae k oF

kr

Forester Creek

Gray Creek

Ottoway Creek

Red Creek

Red

Peak

Gray

Peak

Merced

Peak

Isberg

Peak

Ottoway

Peak

Mount

Clark

M

Quartzite Peak

Triple

Divide Peak

Yosemite

Wilderness

An

W

SOURCE: NPS, 1997, 2011

Map Area

Segment

4

Segment

3

Segment

2 Segment

1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment
Little Yosemite Valley

Lost Lake

Merced River

Ech

Little Yosemite Valley

Ranger Station

Little Yosemite Valley

Backpackers Campground

Cascade

Bunnell

Sunrise Creek

Moraine Dome

Campground

Backpackers

Meadow- West

Little Yosemite Valley Little Yosemite Valley

Meadow- East

JohnMui r Trail

John Muir Trail

Ha lf Dome

Dome

Half

Liberty

Cap

Clouds

Rest

Moraine

Dome

Domes

Quarter

Bunnell

Point

Cascade

Cliffs

Bunnell

Cliff

Snow Creek Falls

Tenaya Creek

C

wonS eek r

Yosemite

Wilderness

SOURCE: NPS, 1997, 2011

0 

Map Area

Segment

4

Segment

3

Segment

2 Segment

1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment
Analysis Topics: Natural Resources 

Vegetation and Wetlands 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-195

obligate wetland species indicates that these meadows stay wet later into the growing season when 

compared to many of the other meadows along Segment 1. 

The extent of conifer encroachment in subalpine meadows varies widely, with some meadows 

(Merced Lake–East and Little Yosemite Valley–East) having no seedlings present and others (Turner 

Lake, Triple Peak-North and Red Peak-South) having three to four times the extent of conifer 

encroachment relative to other subalpine meadows. 

With the exception of the Little Yosemite Valley area, nonnative species are uncommon in meadows 

of the Merced River high country, and were not observed in any meadows along the Merced River 

above Washburn Lake. Nonnative Kentucky bluegrass (Poa pratensis ssp. pratensis) is found in drier 

areas of Little Yosemite Valley–East and is found in abundance around cabins at Merced Lake High 

Sierra Camp (Colwell and Taylor 2011), while the nonnative bull thistle (Cirsium vulgare) is found in 

the wooded area outside Merced Lake East Meadow. Other nonnative plants, including velvet grass 

(Holcus lanatus), common mullein (Verbascum thaspus), yellow salsify (Tragopogon dubius), prickly 

lettuce (Lactuca serriola), timothy (Phleum pretense), and dandelion (Taraxacum officinale) were 

detected outside of the meadows during surveys in 2006–2010 in Little Yosemite Valley (Ballenger et 

al. 2011). These nonnative populations are controlled through annual hand-pulling. 

The 2010 Assessment of Meadows in the Merced River Corridor, Yosemite National Park (Ballenger et al. 

2011) concluded that pack stock impacts or vulnerability to impact in subalpine meadows were a 

primary consideration for management of these areas. Potential issues related to pack stock use raised 

in the study include levels of use, timing of use, and suitability for use. The issues are particularly 

important for those subalpine meadows (such as Merced Lake and Doc Moyle’s) with wet soils 

supporting hydrophytic sedge species. 

Only limited data are available on the extent of stock use in Segment 1 of the Merced River. Table 9-4

shows the total annual number of stock-use nights within Segment 1 by NPS administrative and 

commercial operators. The majority of stock-use nights occur at Merced Lake-East. The Assessment of 

Meadows in the Merced River Corridor found that pack stock impacts were absent or uncommon in most 

subalpine meadows, with the exception of Merced Lake–East, which had the highest levels of pack stock 

use of any meadow in the corridor, and Doc Moyle’s–West, which had much lower levels of use and 

associated impacts. The study hypothesized that pack stock use contributes to lower vegetation cover 

and higher levels of bare ground at Merced Lake–East. The two meadows nearest Merced Lake–East 

(Merced Lake–West and Merced Lake–Shore) exhibited higher vegetative cover and lower bare ground 

levels when compared to Merced Lake–East, even though they had the same dominant plant species. 

Although grazed in the past, these two meadows were closed to stock use in the 1990s due to concerns 

over deteriorating conditions. Ballenger et al. (2011) concluded that these two meadows appeared to 

have recovered from previous stock impacts, and that they could provide a comparative baseline when 

monitoring conditions in Merced Lake–East. The study also found that Doc Moyle’s–West may be 

recovering from heavy use of the site as a pack camp in the mid 20th century. Scattered signs of stock use, 

such as hoof punches and/or manure, were observed in five other subalpine meadows (Washburn Lake, 

Triple Peak, Merced Lake–Shore, Triple Peak–South, and Turner Lake). These signs are likely from 

stock use prior to 2010, as those meadows have no recorded 2010 stock use. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-196 Merced Wild and Scenic River Comprehensive Management Plan / DEISTABLE 9-4: STOCK-USE NIGHTS WITHIN SEGMENT 1 BY LOCATION (2004 TO 2010)a

Wilderness 

Stock Campsite 

Areas 

2004 2005 2006 2007 2008 2009 2010 Total 

2004 to 

2010 High 

Commercially 

Guided Pack Trips 

Commercially 

Guided Pack Trips 

Commercially 

Guided Pack Trips 

Commercially 

Guided Pack Trips 

Administrative

b

Total 

Commercially 

Guided Pack Trips 

Administrative

b

Total 

Commercially 

Guided Pack Trips 

Administrative

b

Total 

Commercially 

Guided Pack Trips 

Administrative

b

Total Averagec

Horsethief 12 12 8 8 50 50 21 21 91 13 50 Merced Lake – East 350 350 96 96 410 410 28 300 328 1184 296 410 Washburn Lake 23 36 20 28 28 28 28 135 19 36 Doc Moyle’s 19 33 33 0 6 6 58 8 33 Echo 36 20 20 56 8 36 Total 42 72 20 45 350 395 56 96 152 50 410 460 83 300 383 1524 344 460 NOTES: a Data shows the number of overnight stays by stock within the river segment. One stock-use night is equivalent to one overnight stay by one head of stock. Concessioner’s stock used to supply the 

Merced Lake High Sierra Camp is not shown in the table. 

b Administrative use within the Merced River corridor was not tracked by NPS staff until 2007. The stock-use night estimates do not include ranger patrols or sawyers but predominantly show stock use 

providing operational support for the NPS ranger operations and the backpacker campground facilities within Little Yosemite Valley and at Merced Lake. 

c Average is for the stock use between 2007 and 2010. Although an average is presented for each wilderness stock campsite area, one caveat is necessary: year-to-year NPS administrative stock use 

levels can vary widely based on management and project work performed that year. 

SOURCE: NPS 2011 
Analysis Topics: Natural Resources 

Vegetation and Wetlands 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-197

There are no formal trails present in any of the subalpine meadows surveyed for the study. Most 

subalpine meadows had little or no informal trails present. Five subalpine meadows had some informal 

trails present, with Merced Lake–Shore having the most, likely due to its proximity to Merced Lake 

High Sierra Camp. The study could not differentiate between human and equine trailing on those sites 

with pack stock use (Ballenger et al. 2011). Table 9-5 provides details on informal trails in subalpine 

meadows of the Merced River corridor. 

TABLE 9-5: INFORMAL TRAILS IN SUBALPINE MEADOWS

Meadow Name 

Informal Trails 

(length in meters) 

Doc Moyle’s–West 205.8 

Doc Moyle’s–East 60.6 

Little Yosemite Valley–West* 0 

Little Yosemite Valley–East 0 

Merced Lake–Shore 1,637.5 

Merced Lake–West 0 

Merced Lake–East* 144.0 

Red Peak–North 0 

Red Peak–South 0 

Triple Peak–North 0 

Triple Peak–South 0 

Turner Lake 0 

Washburn Lake 144.2 

NOTE: Includes informal trails within 50 meters of each meadow. * Indicates site was largely inundated 

at time of survey, so detection of informal trails may not have been possible. 

SOURCE: Ballenger et al. 2011 

Alpine Plant Communities. Alpine plant communities within the upper Merced River corridor are 

limited to alpine snow patch communities. These communities are above tree line dominated by 

herbaceous vegetation that has adapted to a very short growing season. Sites are seasonally saturated 

by snowmelt. 

Chaparral Communities. Chaparral communities along the upper Merced River are characterized by 

montane chaparral (NPS 1997c). Montane chaparral is most often found on south-facing slopes in the 

coniferous forest zones. Since the majority of the annual precipitation comes as snow, there is a 

shorter growing season than in lower elevation chaparral communities. Plant species typical of this 

diverse community include mountain whitethorn (Ceanothus cordulatus), greenleaf manzanita 

(Arctostaphylos patula), chinquapin (Chrysolepis sempervirens), bitter cherry (Prunus emarginata), 

buckbrush (Ceanothus cuneatus), deerbrush (Ceanothus integerrimus), currant (Ribes sp.), huckleberry 

oak (Quercus vacciniifolia), mountain mahogany (Cercocarpus ledifolius), and lupine (Lupinus spp.). 

Within the alpine and upper subalpine zones, montane chaparral is sparsely vegetated and typically 

consists of small, low-growing plants at the base of rocks or other semiprotected sites where sediment 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-198 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

and water collect and thin crusts made up of mosses, lichens, algae, and bacteria are present. These 

organisms form a biotic layer over unvegetated areas between shrubs, grasses, and flowering plants in 

undisturbed arid and semiarid lands of the world, including the alpine zone of the upper Merced 

River. These crusts function as soil builders. With a drop in elevation, chaparral plant communities 

dominate exposed slopes. Species in these areas are often prostrate (low growing), with occasional 

wind-pruned pines intermixed. Examples of chaparral communities occur near the confluence of the 

Merced Peak and Triple Peak Forks. Lower-elevation talus and scree fields colonized by dense 

shrubby trees and chaparral slowly succeed to coniferous forest communities. 

Subalpine Coniferous Forest. Subalpine coniferous forests are relatively open and exposed, and 

increase in density along river and stream channels. The forest understory is naturally sparse and 

ranges from barren rock to sparse shrubs and grasses. The subalpine zone is characterized by long, 

severe winters and brief, cool summers. Trees in this zone range between 10 and 70 feet in height and 

are typically long-lived. Intensely strong winds on exposed ridges near treeline cause stunted forests, 

typically found at timberline, where trees are continually exposed to harsh weather conditions. 

Lodgepole pine (Pinus contorta ssp. murrayana) and whitebark pine (Pinus albicaulis) dominate 

subalpine coniferous forests, with mountain hemlock a common associate. 

Lodgepole pine forest generally occurs at elevations with long, snowy winters, late-season snowpack, 

and cool, dry summers. Lodgepole pine often grows in dense, pure or almost pure stands. This species 

tolerates large variations in soil and moisture, but most commonly occurs on rocky, well-drained soils. 

At its lower limit, lodgepole is found in valley bottoms, cold basins, and wet areas around meadows 

surrounded by upper montane coniferous forest. The riparian type occurs at the same elevation with a 

mixture of understory shrubs and herbaceous perennials, surrounded by red fir. The more abundant 

xeric type is found on porous, decomposed granite substrate. 

Whitebark pine forests occur on shallow, rocky soils just below treeline. The growing season is very 

short due to long, cold winters, and there is the possibility of snow or frost likely in any month. In 

many cases, whitebark pine forms pure stands of widely spaced trees. It can also form dense shrub-like 

krummholz about 3 feet high. Major associates include mountain hemlock and lodgepole pine. 

Although Sierra juniper (Juniperus grandis) occurs throughout the upper Merced River zone, 

unusually large specimens of this species occur above Washburn Lake. Typical trees measure 30 feet in 

height and 6–8 feet in diameter. 

Upper Montane Coniferous Forest. Western white pine (Pinus monticola), Jeffrey pine (Pinus jeffreyi), 

red fir (Abies magnifica), sugar pine (Pinus lambertiana), incense cedar (Calocedrus decurrens), lodgepole 

pine, and mountain hemlock (Tsuga mertensiana) dominate the higher elevations above Little Yosemite 

Valley. The red fir community occurs in the area of greatest snowfall accumulation in the Sierra Nevada. 

Snow generally remains until June and the growing season is concentrated into mid-summer. The red fir 

community usually occurs in large stands separated by barren areas, ridges, meadows, and dense stands 

of lodgepole pine, which occupy poorly drained sites. These dense forests, with frequently overlapping 

narrow crowns, cast deep shade on the forest floor. The understory is nearly absent and ground cover 

consists of abundant needle litter and fallen branches. Common associates in the red fir community 

include white fir, western white pine, and at the upper limit, lodgepole pine. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-199

Western white pine occurs intermittently or as a co-dominant in the red fir community. On a small 

number of south- or west-facing slopes, it forms the dominant forest cover and may even occur in pure 

stands. This community generally occupies dry rocky areas and is composed of large, widely spaced 

trees. Often there is an understory of dwarfed montane chaparral composed of pinemat manzanita 

(Arctostaphylos nevadensis) and mountain whitethorn. 

White fir occurs in the 6,000- to 7,000-foot elevation range along the river corridor. The diversity of 

both forest-dominant and understory species above Little Yosemite Valley exemplifies the variability 

of vegetation through this zone of the Sierra Nevada range. Understory species in the upper montane 

coniferous forests include a mix of scrub and chaparral, as well as young conifers and fern dells. 

Species composition is diminished in localized areas such as Merced Lake High Sierra Camp (denuded 

understory) and the burn area within Echo Valley (even-aged stands of young conifers). 

Lower Montane Coniferous Forest. The lower montane coniferous forest along the upper Merced 

River is dominated by ponderosa pine (Pinus ponderosa) at lower elevations and Jeffrey pine at higher 

elevations, along with other coniferous species such as white fir, incense cedar, and sugar pine. This 

community favors dry, cold, well-drained sites, especially slopes, ridges, or cold air accumulation 

basins. In some areas, notably the south-facing slopes below Half Dome, it can form vast stands. In the 

more xeric and lower elevational limit of its habitat, Jeffrey pine is associated with dense understory 

stands of chaparral. In more mesic sites, or at higher elevations, it intergrades into upper montane 

coniferous forest. The plant species composition of the forest varies with elevation, slope, aspect, soils, 

water availability, and past and ongoing disturbance. 

Little Yosemite Valley is dominated by mixed conifer communities of ponderosa pine, incense cedar, 

sugar pine, and occasional California black oaks and canyon live oaks. The most common understory 

shrubs are Mariposa manzanita (Arctostaphylos viscida ssp. mariposa), deerbrush, and bear-clover 

(Chamaebatia foliolosa). With a descent in elevation from the upper reaches of the Merced River into 

Little Yosemite Valley, the impacts associated with visitor use become more apparent. Forests to the north 

of the Merced River experience relatively heavy use (along major trail routes and camping sites), typically 

have little understory vegetation, and are dense with young trees, dead material, and ladder fuels. Forests 

south of the river receive almost no use and are more rich and pristine in nature. Typical nonnative species 

in this coniferous forest include European annual grasses, bull thistle, and common mullein. 

Lower Montane Broadleaf Forests. Lower montane broadleaf forest along the upper Merced River 

includes areas dominated by California black oak (Quercus kelloggii) or canyon live oak (Quercus 

chrysolepis). These areas are not extensive in the upper Merced River corridor and only occur at the 

lowest elevations of these segments. This forest becomes more widespread at lower elevations. Lower 

montane broadleaf forests occur as persistent stands dominated by California black oaks or canyon 

live oaks with scattered pines. Most stands occur on mountain slopes, benches, and canyon bottoms. 

Primary associate species include white fir (Abies concolor), incense cedar, sugar pine, and Jeffrey pine. 

Wetlands and Riparian Habitats. Numerous small wetland meadows3 and adjacent riparian habitat 

are present in the upper reaches of the Merced River corridor above Nevada Fall. These high-elevation 

 

3 Not all meadows along the Merced River corridor can be classified as wetlands. For a more general discussion of 

meadows, please refer to “Meadow Plant Communities” above. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-200 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

meadows typically occur on fine-textured, permanently to semi-permanently wet soils generally 

associated with perennial streams, seeps, lake margins, or depressions. Vegetation consists of lowgrowing, native, tussock-forming grasses, sedges, rushes, and perennial herbs. Within the alpine zone 

(generally above 9,600 feet — the highest portion of the Merced River’s headwaters), wetland meadows 

often form thin margins around small glacial lakes. At lower elevations (such as Merced and Washburn 

lakes), subalpine wetland meadows (7,000–9,600 feet) link the aquatic river and lake habitats with the 

drier upland forests. In-lake vegetation is typically limited to rooted aquatic grasses, floating vascular 

plants, and algae. Meadow communities border lake margins, providing important wildlife habitat. 

These wetland plant communities are hydrologically driven by the groundwater and flooding regime of 

the Merced River (NPS 1997; Ballenger et al. 2011; Sawyer et al. 2009). For a more detailed discussion 

of the current condition of meadows in the upper Merced River watershed, please refer to “Meadow 

Plant Communities” above. 

Much of the Merced River above Nevada Fall is bordered by a narrow riparian zone influenced by 

stream gradient, slope, sedimentation, and aspect. High-elevation tributaries to the Merced River (e.g., 

Merced Peak Fork and Triple Peak Fork) are sparsely vegetated with scattered patches of alpine 

riparian scrub and alpine willow thickets. As the river descends and the gradient becomes gentler, 

lodgepole pines, aspens (Populus tremuloides), willows (Salix spp.), and alders (Alnus spp.) become more 

prevalent. Willows often colonize where point bars form (at the margins of, or within, the river channel). 

Riparian species often intergrade with coniferous forest at or near the river’s upper banks (NPS 1997; 

Sawyer et al. 2009). Riparian communities of the upper Merced River are generally intact, except in a 

few locations where human use is intense. 

Segment 2: Yosemite Valley 

Yosemite Valley is a broad, flat-bottomed valley formed by glaciation and subsequent alluvial 

deposition. Yosemite Valley is in the lower montane mixed conifer zone, and vegetation is classified 

into three broad types: meadow, lower montane broadleaf forest, and lower montane coniferous 

forest. California black oak forest is a major component of the broadly defined lower montane 

broadleaf forest. Because the NPS considers California black oak a highly valued biological and 

cultural resource, this community is described separately from other lower montane broadleaf forest 

communities. There are also areas categorized as barren, which in Yosemite Valley include talus 

slopes, developed sites, and other unvegetated areas. Along many segments of the Merced River 

corridor in Yosemite Valley, the river is bordered by a narrow riparian zone and small wetlands. In 

addition, many of the larger meadows of Yosemite Valley support wetland areas. As mentioned above, 

even though riparian and wetland areas are not classified independently under the eight broad 

vegetation types used in the parkwide vegetation map, they are discussed in depth in the “Wetland and 

Riparian Habitats” section below. 

Fire History of Yosemite Valley: For more than 4,000 years, traditionally associated American Indians 

relied on Yosemite Valley’s meadows and oak woodlands to provide food, medicine, and materials for 

baskets, string, and shelter. Yosemite's early inhabitants periodically set fires to promote the growth 

milkweed, dogbane, sedge root, and bunch grass (Gassaway 2005). Pre Euro-American fire regimes were 

characterized by frequent late season fires that varied in extent from local spot fires to larger burns 

(Taylor 2006). The presence of large diameter California black oak, ponderosa pine, incense cedar, and 
Analysis Topics: Natural Resources 

Vegetation and Wetlands 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-201

Douglas-fir in photographs of Yosemite Valley taken in the 1860s and 1870s (Gibbens and Heady 1964; 

Gruell 2001) suggest that surface fires killed mainly seedlings and saplings. Thus, frequent fire promoted 

development of open forest conditions with a predominance of large diameter trees. When EuroAmericans began living in Yosemite Valley in the 1850s, traditional burning practices were stopped and 

fire suppression became official policy until the 1970s. Fire was a key disturbance process that influenced 

forest structure and composition in Yosemite Valley prior to Euro-American settlement. Fire regimes 

changed dramatically after Euro-American settlement as did the role of fire in shaping vegetation 

structure and dynamics. The most conservative estimate of how often sites burned during the pre EuroAmerican period indicates that forested areas in the Valley burned every 11-14 years (Taylor 2006). 

Meadow Plant Communities. Low-elevation meadows on the Merced River floodplain are 

hydrologically driven communities that depend on river processes, including the frequency, duration, 

timing, and magnitude of flooding, and frequent low-intensity broadcast fires. The meadows in 

Yosemite Valley form transition zones from drier upland and California black oak communities to 

wetter riparian communities. The aquatic food chain in the Merced River is dependent on a 

connection with overflow channels in the meadows, which spill over during periods of high water, 

releasing concentrated food sources into the river. 

Meadows in Yosemite Valley are larger in size than most mid-elevation meadows throughout the 

region and thus are rare and unusual at a regional scale (NPS 1997, figure 9-10). In addition, meadows 

in Yosemite Valley are highly diverse, both from a structural point of view, as the meadows contain a 

wide variety of microhabitats, and from a species point of view, as the meadows support high numbers 

of different native plant and animal species. About 30 different sedge species have been collected in 

Yosemite Valley meadows, which is considered by experts in the genus to be an exceptional degree of 

diversity (Ballenger et al. 2011). These meadows also support special status animal species, illustrating 

the exceptional species richness of Yosemite Valley. These attributes combine to make Yosemite 

Valley’s meadows an extraordinary example of a regionally rare ecosystem, and contribute to the 

river’s biological ORV. 

The water tables in Yosemite Valley remain at or near the surface throughout the growing season. An 

accumulation of organic matter is typical in these meadows. Sedges, grasses, and other perennial and 

annual herbs form a dense cover. The most common sedges in many meadows include rough sedge 

(Carex senta) and wooly sedge (Carex pellita); these species occur in the most mesic areas. The most 

common grasses found in meadows include beardless wild rye (Elymus triticoides) and the nonnative 

Kentucky bluegrass. These grasses occur in dry portions of meadows where surface moisture is 

depleted during the growing season. Grasses commonly dominate the dense to moderate cover of 

perennial and annual herbs. 

Over the past century the acreage of meadows in Yosemite Valley has decreased (figure 9-11) due to 

conifer encroachment (Gibbens and Heady 1964; Heady and Zinke 1978). Cooper and Wolf (2008) 

suggested that conifers have likely colonized former meadows for several reasons: (1) the installation of 

drains, water diversions, and other facilities caused hydrologic changes that lowered the summer water 

table; (2) the cessation of burning by American Indians allowed tree seedlings to persist; (3) disturbance 

caused by plowing meadows and planting hay crops and apple orchards allowed conifers to invade the bare 

soils after the widely rooted, sod-forming meadow species were destroyed; and (4) placement of fill to raise 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-202 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

the ground elevation allowed upland species to invade. The widening of the Merced River — attributable 

to trampling on riverbanks, subsequent loss of vegetation, and accelerated erosion — also had an effect 

on natural river processes such as flooding, and natural erosion and sediment deposition (Madej 

1991). These processes shape the dynamic habitat that sustains riparian vegetation and supply water to 

meadow communities. 

Historic photos and accounts document the condition of Yosemite Valley meadows in relation to 

conifer encroachment through time. In 1866, State Geologist J.D. Whitney (1868) mapped 745 acres of 

meadows in Yosemite Valley. In 1937, NPS type mapping projects calculated 327 total meadow acres 

in Yosemite Valley. In 2010, botanists mapped 269 total meadow acres, a 64% decrease from the 

1866 Yosemite Valley meadow (Ballenger et al. 2011) (figure 9-11). 

The recently completed 2010 Assessment of Meadows in the Merced River Corridor, Yosemite National 

Park (Ballenger et al. 2011) provides details on the current condition of meadow habitats in Yosemite 

Valley. The study examined a wide variety of attributes including vegetation, wetland extent, bare 

ground, nonnative species, conifer encroachment, and meadow stream condition. Disturbance from 

small mammal burrows, informal trails, and pack stock use was also documented. 

Mean vegetation cover in Yosemite Valley meadows ranged from 50%–70%, with El Capitan and Leidig 

meadows having the lowest mean vegetation cover and Cook’s Meadow having the highest. The authors 

found that graminoid species dominated Yosemite Valley meadows, which are a healthy component of 

meadow vegetation. However, nonnative plant species are common in Yosemite Valley meadows, with 

the highest extent of nonnatives in Stoneman and El Capitan meadows. The study also compared mean 

cover of nonnative plants across all meadows for different surface soil moisture categories and found 

that nonnative plant cover was lowest in saturated and inundated plots. Dry and moist plots had two to 

three times the cover of nonnative plants as plots with early-season saturated or inundated soils. Because 

El Capitan and Stoneman Meadows also had the lowest proportion of wetland area of Yosemite Valley 

meadows, the study suggests a connection between the extent of perennially wet soils and nonnative 

species in Yosemite Valley. Kentucky bluegrass was the most common nonnative recorded, which 

outcompetes native meadow species when soil moisture is reduced (Martin and Chambers 2001; Kluse 

and Allen-Diaz 2005). So far, most nonnative plants currently present in Yosemite Valley meadows are 

not well adapted to outcompete native plants in the wettest portions of the meadows with the exception 

of Kentucky blue grass and velvet grass (Holcus lanatus), and aggressive non-native plant which prefers 

wet conditions and is already established in Yosemite Valley). Close attention to early detection and 

eradication of nonnative meadow plants will help keep additional species and populations from 

encroaching into wetlands, and maintaining and restoring the hydrologic regime of Yosemite Valley 

meadows may help sustain native meadow vegetation (Ballenger et al. 2011). 

Across all Yosemite Valley meadows surveyed, 50% of plots were considered wetlands under the 

Cowardin standards, based on dominant plant species and wetland indicator ratings. Leidig, Cook’s, 

and Sentinel meadows had the highest proportion of wetland plots (84-86%). El Capitan and 

Stoneman meadows had the lowest proportion of wetland plots, with 50% and 52% respectively. 

Conifer seedlings are more frequent in El Capitan and Stoneman meadows than in Leidig and Sentinel 

meadows, presumably due to a longer inundation period in the latter set of meadows. The seedlings of 

many tree species cannot survive long periods of inundation (Koxlowski 1997). 
Bridalveil Creek

Nor ths di e Drive

41

al V el y Loop Trail

El Capitan Trail

Wawona Road

Yosemite

Wilderness

Yosemite

Lodge

Gunsight

Taft

Point

Eagle

Peak

El

Capitan

K P

Pinnacle

Sen

Ro

Lower

Brother

Leaning

Tower

The

Fissures

Columbia

Point

Three

Brothers

Split

Pinnacle

Middle

Brother

Cathedral

Rocks

Cathedral

Spires

Pohono Trail

Souths di e Dr vi e

Merced River

Eagle Creek

Ribbon

Fall

Sentinel

Fall

Bridalveil

Fall

Lower

Yosemite Fall

El Capitan

Meadow

Leidig

Meadow

Sentinel

Meadow

Bridalveil

Meadow

Slaughterhouse

Meadow

SOURCE: NPS, 1997, 2010, 2011; Hoffman/State Geological Survey, 1867

Map Area

Segment

4

Segment

3

Segment

2 Segment

1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment
THIS PAGE INTENTIONALLY LEFT BLANK 
Analysis Topics: Natural Resources 

Vegetation and Wetlands 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-205

SOURCES: Whitney 1868; Gibbens and Heady 1964; Heady and Zinke 

1978; Cooper and Wolf 2008; Ballenger et al. 2011. Figure 9-11

Meadow Acreage in Yosemite Valley 

(1866-2011)

Informal trails are common in Yosemite Valley. The 2010 Assessment of Meadows in the Merced River 

Corridor, Yosemite National Park (Ballenger et al. 2011) found that bare ground from informal trails 

was highest in El Capitan, Sentinel, and Bridalveil meadows. Cook’s and Stoneman meadows had the 

lowest levels of bare ground from informal trails, possibly due to the presence of elevated boardwalks 

that concentrate visitor foot traffic, discouraging visitors from venturing cross country through the 

meadows and mitigating trampling effects. Although the meadows of Yosemite Valley have experienced 

a variety of human-related impacts over the past 150 years, the remaining meadows are still largely intact 

and are some of the most ecologically valuable meadows in the Sierra Nevada. The NPS is implementing a 

number of management programs to restore meadow communities along the Merced River within 

Yosemite Valley, including prescribed burning, treatment of nonnative plant populations, and restoration 

of native plants. For example, tens of thousands of conifer seedlings and saplings were removed from 

Yosemite Valley meadows in the last decade. Populations of high-priority nonnative species, such as 

Himalayan blackberry (Rubus armeniacus), bull thistle, St. John’s wort (Hypericum perforatum), and 

velvet grass, were mapped and many of these populations were treated (Ballenger et al. 2011). 

Other beneficial projects include the Cook’s Meadow Restoration Project and the Eagle Creek 

Restoration Project, which were specifically designed to enhance meadow and riparian habitat. The 

Cook’s Meadow project restored meadow hydrology by filling ditches and removing an abandoned 

roadbed. The Eagle Creek Restoration Project enhanced riparian streambank integrity by recontouring 

and revegetating eroded streambanks, de-compacting soils, and constructing fencing to direct visitors to 

areas that could accommodate higher levels of use such as sandbars. In Cook’s Meadow, the NPS 

excavated paved interpretive trails that crossed the meadow and replaced them with elevated 

boardwalks. In Sentinel Meadow, the NPS constructed one boardwalk and fencing along the strip 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-206 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

parking area, helping to discourage the use of 29 informal trails by delineating access. Similarly, in 

Stoneman Meadow, the NPS constructed a boardwalk across the meadow to further discourage the use 

of 25 informal trails.

Lower Montane Broadleaf Forest. Lower montane broadleaf forest in Yosemite Valley includes 

areas dominated by California black oak or canyon live oak. This community is transitional between 

low-elevation broadleaved forests and higher elevation coniferous forests. Canyon live oak 

communities grow on both north- and south-facing talus slopes and often form pure or almost pure 

stands. Fires in this community are infrequent but intense, with a fire return interval of 20–50 years on 

south-facing slopes. Most trees and shrubs in this community crown sprout after fire. 

California Black Oak Stands. California black oak stands are considered a subset of the lower 

montane broadleaf forest. They are discussed independently here because they are considered a key 

element of the river’s cultural ORV. 

Black oak acorn has been an important staple food for Indian people in Yosemite Valley for millennia 

(Anderson 1991; Hull and Moratto 1999). According to Bibby (1994:17), its historic importance is 

likely one reason why acorn, and the cultural knowledge regarding its preparation, has survived 

strongly among the contemporary associated tribes and groups. Although it is no longer a staple food, 

it has become symbolic of ancestral traditions and an important aspect of contemporary culture. For 

example, acorn soup is prepared for special occasions, especially traditional gatherings and ceremonial 

events. Several of the former inhabitants recall gathering acorn with their parents and/or grandparents, 

attesting to the multi-generational historical and place-based personal connections between black 

oaks and the people. Certain groups of trees, or even individual trees, continue to be associated with 

particular individuals who gathered in historic times (Bibby 1994:22). 

California black oaks in Yosemite Valley form open stands of large, stately trees with an herbaceous 

understory. These stands are unique to the valley due to thousands of years of anthropogenic 

activities, including annual burning and removal of young conifers, and are found at the change in 

slope between upland colluvial deposits and lower meadow, water-driven alluvial areas. They form a 

band or ring of oaks around the valley floor, between the upland forest communities and the lowerlying meadow and riparian communities, totaling approximately 126 acres. California black oak stands 

mixed with ponderosa pine are found throughout the valley, and areas of California black oak with 

development are found in the east Valley, totaling an additional 280 acres. California black oaks also 

grow in dense stands on talus slopes near drainages. 

The current structure of the California black oak population in Yosemite Valley follows a familiar 

pattern for oak species throughout California – a more or less predicted frequency distribution of 

adults but few to any saplings and young adults, but usually many young seedlings. California black 

oak communities in Yosemite Valley have experienced a decline in population size, density, vigor, 

recruitment rates, and stand structure. The decline has been caused by changes in natural or cultural 

fire processes, encroachment by conifers, browsing by deer and rodents, and from development and 

unmanaged visitor use in the early and mid-20th century (Fritzke 1997). Oak woodlands are also some 

of the most ecologically transformed terrestrial ecosystems in the Sierra Nevada due to alterations of 
Analysis Topics: Natural Resources 

Vegetation and Wetlands 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-207

natural processes, development, and introduction of nonnative species. The conversion of oak 

woodlands has also had a substantial effect on wildlife species (UC Davis 1996). 

California black oak communities are adapted to frequent low-intensity fires, similar to upland mixed 

conifer communities. Under natural conditions, the return interval for fire is estimated at 8–12 years 

(NPS 1990). The disruption of natural and aboriginal fire regimes has led to the rapid decline of black 

oak woodlands in the park (Angress 1985). Nonnative plant species have also become established in 

California black oak communities. Species include annual grasses, black locust (Robinia pseudoacacia), 

and extensive ground-covering stands of Himalayan blackberry. 

Lower Montane Coniferous Forest. Mixed conifer communities are normally dominated by 

ponderosa pine and generally grow at elevations of 3,000–5,000 feet. This habitat also contains incense 

cedar, sugar pine, and occasional California black oaks. The most common understory shrubs are 

Mariposa manzanita, deerbrush, and bear-clover. 

The mixed conifer community is naturally adapted to low-intensity, frequent fires. Nearly 100 years of 

fire suppression has resulted in a change from open forest to dense thickets of shade-tolerant tree 

species, including incense cedar, white fir, and Douglas-fir (Pseudotsuga menziesii). Under natural 

conditions, the return interval for fire is estimated at 8–12 years (NPS 1990). Present conditions, 

however, often generate fires of much greater intensity than under a natural fire regime. The intensity 

of the 1990 A-Rock Fire in the Foresta area was partially due to these conditions. Most undeveloped, 

mixed conifer areas of Yosemite Valley are now managed through a combination of mechanical 

removal of hazardous fuel and prescribed burning. These treatments simulate the natural and 

anthropogenic fire regimes of the Valley and help decrease stand densities to more natural levels. 

In Yosemite Valley, the extent of the annosus root disease is unusual; there are only a few other large 

populations of this species of root rot on the western side of the Sierra Nevada (NPS 1998B). Annosus 

root disease is a widespread native fungus. In pines, the fungus first spreads through the root system, 

attacking the inner bark and sapwood, killing these tissues. Within 2 to 6 years after initial infection, 

the fungus reaches the root crown and girdles the tree. The tree dies, but the fungus remains active as a 

saprophytic, wood-decaying organism within roots and the butt of the dead tree and spreads to the 

root systems of adjacent trees. This fungus also spreads more readily in tightly spaced trees. 

Yosemite has unnaturally dense stands of conifers in former California black oak, meadow, and 

riparian areas that have a high water table and frequent flooding. The conifer forest in Yosemite Valley 

may not be sustainable because of these unusually large centers of annosus. Significant annosus 

infestation centers in Yosemite Valley include former Upper River and Lower River campgrounds and 

Yellow Pine Campground, portions of Yosemite Lodge, and most of the Taft Toe area. Existing 

annosus centers in developed areas can be mitigated by landscaping with species that are not 

susceptible to infection, such as California black oak, canyon live oak, and big-leaf maple. 

Nonnative, or introduced, plant species have become established in the mixed conifer zone, although 

not to the extent they have in meadows and California black oak communities. These species are the 

result of either deliberate or accidental introductions and are not part of the naturally evolved 

community. Many of these are indicators of past agricultural activities that occurred throughout the 

area. Approximately 180 nonnative species have been identified in the park, primarily in the 
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chaparral/oak and mid-elevation forests (Fritzke and Moore 1998). In the upland plant communities 

of Yosemite Valley, nonnative species are generally herbaceous and associated with ground 

disturbance (one-time or recurring). Typical species include European annual grasses and bull thistle. 

Wetlands and Riparian Habitats. Wetlands in Yosemite Valley are formed in low-gradient land 

adjacent to the Merced River, its tributaries, or other bodies of water that are, at least periodically, 

influenced by flooding or high water tables. 

Wetlands within Yosemite Valley have undergone systematic alteration since the middle of the 

19th century as they were grazed, farmed, and used as recreational sites and corridors for travel. One 

of the earliest impacts on wetlands in Yosemite Valley occurred in 1879, with the blasting of El Capitan 

moraine in the west Valley. This action lowered the base hydrologic level and caused the Merced River 

to downcut several feet (Milestone 1978; NPS 1992). Vegetation in adjacent wetlands was probably 

altered, and wetland function would have been further compromised by actions designed to dewater 

these areas. Impacts on wet meadows would have been most severe immediately upgradient of the 

blast (El Capitan Meadow) and from that point upstream. The blasting of the moraine would have had 

minimal impact on Sentinel, Cook’s, Stoneman, and Ahwahnee meadows. 

Other alterations that took place in the early 20th century include drainage ditches that were 

constructed to dewater wet meadows to reduce mosquito breeding areas and provide open land for 

grazing and agriculture. Many of these drainage ditches remain in place and continue to dewater 

meadows in Yosemite Valley. Road construction has involved drainage measures and diversion of 

surface water adjacent to many of the valley’s wetlands. Wetlands are fragmented by roads, trails, and 

infrastructure. This wetland complex was formerly much more interrelated and contiguous. Evidence 

of the impact of roads can be seen in Sentinel, El Capitan, and Stoneman meadows. 

Riparian zones in Yosemite Valley extend outward from bank edges of the Merced River and its 

tributaries into adjacent meadow and forest communities. Riparian ecosystems play a critical role in a 

variety of processes. Situated at the interface between terrestrial and aquatic ecosystems, the riparian 

zone acts to buffer hydrology and erosional cycles, control and regulate biogeochemical cycles of 

nitrogen and other key nutrients, limit fire movements, and create unique microclimates for animal 

species (Rundel and Stuner 1998). 

Riparian zones in Yosemite Valley are characterized by broadleaf deciduous trees, such as white alder 

(Alnus rhombifolia), black cottonwood (Populus trichocarpa), big-leaf maple (Acer macrophyllum), 

white fir, and willow species. Riparian areas within the valley are rich in species diversity and structure. 

Riparian vegetation is regularly disturbed by the deposition and removal of soil and the force of 

floodwaters. Plants in this zone colonize newly formed river-edge deposits readily. The distribution of 

riparian communities varies with soil saturation and frequency of disturbance. For example, big-leaf 

maple riparian forests grow on moist gravelly soils in protected spots on alluvial soils bordering 

streams, whereas sandbar willow woodlands occur on point and mid-channel bars that are washed 

over annually by spring floods (NPS 1994b). 

Riparian communities are among the most productive and biologically diverse in Yosemite Valley. For 

much of the 20th century, these areas were among the most affected due to their proximity to water 

and the effects of trampling and the installation and maintenance of aboveground and belowground 
Analysis Topics: Natural Resources 

Vegetation and Wetlands 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-209

infrastructure, which caused dewatering of riparian areas. Restoration efforts have generally been 

successful at improving the overall condition of the Valley’s riparian communities. However, certain 

riparian areas within the Valley continue to experience impacts. For example, NPS staff continues to 

observe vegetation trampling and bank erosion from heavy use along the following areas: between 

El Capitan Bridge and Clark’s Bridge, Clark’s Bridge and Sentinel Bridge, and Happy Isles Road Bridge 

and Clark’s Bridge; Cathedral, Swinging, Sentinel bridge picnic areas; and around the Upper Pines and 

Lower Pines Campgrounds and Housekeeping Camp. Additional riparian vegetation impacts are 

occurring along reaches that have been armored by revetments or other defensive structures for the 

protection of structures (i.e., bridges). 

Primary stressors on the condition of riparian habitats along the Merced River are related to high 

recreation use, channel stabilization measures, and dewatering due to infrastructure. Measures to 

stabilize the channel were implemented to limit channel migration in areas where bank erosion was 

observed to protect infrastructure, property, and public safety. These measures, including 

constructing bank revetments and clearing channels of large wood, channelized the river and reduced 

riparian habitat complexity. Riparian wetlands along some reaches are also affected by the proximity 

of roads, bank protection measures that have been installed to protect roads, and numerous turnoffs 

and parking areas that provide easy access to the riparian corridor and the river. The recently 

completed Merced River and Riparian Vegetation Assessment (NPS 2011) evaluated the current 

condition of eight geomorphic reaches of the Merced River and its riparian corridor in Yosemite 

Valley by using a variety of different methods. The study found that riparian and wildlife habitat 

conditions along the Merced River through Yosemite Valley varied by geomorphic reach, and that 

these variations were caused by responses to assorted types of impacts. For example, the reach just 

below Happy Isles has wide riparian buffers with complex physical structure and provided good 

wildlife habitat. Conversely, the stretch just below Tenaya Creek had narrow riparian buffers and low 

vegetation structural complexity, providing poor wildlife habitat. The study found that the primary 

causes of decline of the riparian corridor along the Merced River riparian corridor were related to 

recreation use and the presence of infrastructure, which can limit the development of the riparian 

forest (NPS 2011). This same study observed evidence of at least moderate levels of human use 

throughout most of the study reaches. Areas with moderate to high levels of human use were 

concentrated near the developed areas between Clark Bridge and Sentinel Bridge and areas easily 

accessible from adjacent roads. Bank erosion was observed throughout the study reaches, particularly 

near bridges, recreation facilities, and around some meander bends. Areas with moderate to high 

human use also generally had fewer co-dominant species and generally exhibited lower riparian 

community structure complexity (NPS 2011). 

Over the past two decades, the NPS has undertaken numerous efforts to restore the underlying natural 

processes that sustain wetlands and riparian habitats in Yosemite Valley. These efforts include 

prescribed burns, invasive plant eradication, fencing, and increasing inundation levels through 

restoration of natural drainage patterns, among others. A more detailed description of past and 

present restoration projects is included in the Merced River and Riparian Vegetation Assessment

(Cardno ENTRIX 2011) and the Assessment of Meadows in the Merced River Corridor (Ballenger et al. 

2011). These efforts have been successful in improving the overall condition of riparian areas 

throughout the Valley. However, these reports also identify a number of persisting stressors on the 
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9-210 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Valley’s wetlands and riparian ecosystems, such as roads, parking areas, structures, campgrounds, and 

informal trails, which remain to date and are the focus of ongoing park management efforts. 

Segments 3 and 4: Merced Gorge and El Portal 

The Merced Gorge travels through the lower montane forest zone and into the foothill-woodland 

zone, where it enters the El Portal area. Vegetation in the Merced Gorge and El Portal river corridor is 

classified into four broad vegetation types: chaparral, foothill woodland, lower montane broadleaf 

forest, and lower montane coniferous forest. Valley oak (Quercus lobata) woodland occurs in the 

El Portal area (figure 9-12). This community is an element of the broadly defined foothill woodland. 

Because the valley oaks in El Portal are a regionally rare species, this community is described separately 

from other foothill woodland communities. Along these segments, there also are areas categorized as 

barren, which include talus slopes, unvegetated riverine flats, exposed rock, and other unvegetated 

areas. There is a narrow band of riparian vegetation along the river course through the Merced Gorge, 

which is bordered by a dense mosaic of chaparral and forest and woodland communities on the steep 

canyon walls. As mentioned above, even though riparian and wetland areas are not classified 

independently under the eight broad vegetation types used in the parkwide vegetation map, they are 

discussed in depth in the “Wetland and Riparian Habitats” section below. 

All of the communities in this area are adapted to frequent natural fires. Fire suppression has led to 

increased density of vegetation, especially on north-facing slopes. In 1990, the A-Rock Fire burned the 

south-facing slope directly above El Portal. Natural fires probably burned every 5–10 years in grassy 

areas, and every 25–40 years in chaparral areas (van Wagtendonk 1994). 

Chaparral Communities. Chaparral communities along the Merced Gorge are largely confined to the 

canyon sides and open rocky areas. These areas are dominated by evergreen, thick-leaved species. The 

major components of this community are foothill pine (Pinus sabiniana), canyon live oak, interior live 

oak (Quercus wislizeni), Mariposa manzanita, deerbrush, whiteleaf manzanita (Arctostaphylos viscida), 

buckbrush, yerba santa (Eriodictyon californicum), and mountain mahogany. There is often a 

considerable accumulation of leaf litter with little or no understory vegetation. Chaparral communities 

often occur on rockier soils than adjacent foothill-woodlands or lower montane coniferous forests. 

The metamorphic rock formation that crosses the South Fork Merced River downstream of Wawona 

is home to several species of plants that are both rare and apparently specific to this substrate type. 

This same formation crosses the main stem of the Merced River at El Portal, and also is home to rare 

plant species, including state-listed ones (Allium yosemitense, Lewisia congdonii, Eriophyllum 

congdonii), in the vicinity of the river. 

Foothill Woodlands. Foothill woodland communities include interior live oak woodland, foothill 

pine-oak woodland, and interior live oak chaparral. Interior live oak woodland is dominated by 

interior live oak; however, blue oak (Quercus douglasii), California buckeye (Aesculus californica), and 

California bay (Umbellularia californica) are also important. Ponderosa pine occurs as a common 

associated species. Typically dense canopies and abundant, persistent leaf litter occur on dry, rocky 

slopes with little soil development. 
BI

BI

Henness Branch

Merc ed R iver

Forest a Road

140 UV

Murchison

Structures

Trailer Court

El PortalTrailer Court Road

El Portal Wastewater 

Treatment Plant

Foresta

Bridge

Highway 140

Bridge

El Portal

Road

Abbieville

El Portal Administrative Area

Foresta Road

Middle Road

na R

hc re ai l F

Rt a ao d

Cold Canyon Rd

Barium Mine Road

Incline Road

River Road

ChapelLane

Red Bud Lane

Boulder Lane

Buckeye Court

Rocky Road

aL rkspurWay

Rancheria Flat Court 

National Park

Service Warehouse

Rancheria Flat

Old El Portal

Segment

4

Segment

3

Segment

4 Segment

1

Segment

5

Segments

6,7

Segment

8

Map Area

Recreational Corridor Scenic Corridor Wild Corridor

Valley Oak Distribution

GAP Landcover Data (2009)

Yosemite National

Park

SOURCE: NPS, 1997, 2011

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Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-213

Foothill pine–oak woodland is largely confined to the canyon sides and open rocky areas. It is 

dominated by evergreen thick-leaved species. The major components of this community are foothill 

pine, canyon live oak, interior live oak, Mariposa manzanita, deerbrush, buckbrush, and mountain 

mahogany. The vegetative cover is sparse and discontinuous, with an open canopy of emergent foothill 

pine or an understory of nonnative grasses and an abundance of native annual herbs. 

Valley Oak Stands. Valley oak stands are considered a subset of the foothill woodland community. 

Six species of oak grow in El Portal. One particularly noteworthy species is the valley oak, described in 

the next paragraph. The oak canopy provides shade, scenery, and wildlife habitat. The shrub layer 

retains many native elements such as western redbud (Cercis occidentalis), California buckeye, 

Mariposa manzanita, and yerba santa. Undeveloped areas often support a grassy understory that 

consists of mostly nonnative grasses along with native wildflowers. Yellow star-thistle (Centaurea 

solstitialis), tocalote (Centaurea melitensis), and other extremely invasive species have recently become 

established in part of the understory flora. Historic and current development and landscaping have 

introduced many other nonnative species into this community, including the invasive tree-of-heaven 

(Ailanthus altissima), French broom (Genista monspessulana), and numerous herbaceous lawn grasses. 

Fruit trees and other landscape trees are also common. Programmatic efforts to reduce or control the 

spread of invasive species have been in place in Yosemite for several years. 

Valley oaks are a keystone species in floodplain riparian habitats throughout California. A keystone 

species is one whose impact on its community or ecosystem is disproportionately large relative to its 

abundance or total biomass. Endemic to California, valley oak populations have experienced a 

widespread decline throughout the state. The California Native Plant Society considers the valley oak 

plant community, or Quercus lobata alliance, as rare and threatened throughout its range (Sawyer et al. 

2009). Yosemite is home to one valley oak population, at the El Portal Administrative Site. This 

population is unique, as it is geographically isolated from most remaining populations centered in the 

Great Central Valley of California and lies at the extreme eastern boundary for the species’ range. 

The El Portal valley oak population contains trees with sizes ranging from small to very large (up to 

approximately 140 centimeters in diameter). Various factors limit the establishment of valley oaks in 

potential habitat in El Portal. For example, the dirt parking lot across from the train exhibit has 

expanded with cars parking under the dripline of mature oaks and grading has occurred in the area. 

The establishment of new oaks is also likely retarded by deer browsing. The understory of the valley 

oak population is heavily impacted, and an invasion of nonnative Himalayan blackberry exacerbates 

the issue. An additional stressor to the valley oak population is the loss of overbank flooding in the 

El Portal floodplain, due primarily to construction of the Yosemite Valley Railroad terminus and 

Highway 140 (Howard 1992). Despite these issues, the core population retains sufficient integrity as a 

vegetation community to be classified as valley oak woodland in Yosemite’s parkwide vegetation map. 

Lower Montane Broadleaf Forest. Lower montane broadleaf forest in the Merced Gorge includes 

areas dominated by canyon live oak and interior live oak, with scattered groves of California black oak. 

This community is transitional between foothill woodlands and coniferous forests. Interior live oak 

forest is dominated by interior live oak in a dense evergreen forest that forms a closed canopy. It 

ranges in site characteristics from broad alluvial riverbanks to steep, rocky south-facing slopes at lower 
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9-214 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

elevations. Most pure stands of interior live oak are small and appear to be seral stages of oak 

woodland with little herbaceous cover. Common associated species include foothill pine, canyon live 

oak, and blue oak. Understories tend to be brushy with characteristic species consisting of California 

buckeye, western redbud, and poison-oak (Toxicodendron diversilobum). Canyon live oak forest is 

typically found on rocky, steep slopes with little soil development in canyons on north-facing slopes at 

relatively low elevations, and on south-facing slopes at higher elevations. Canyon live oak often forms 

pure or almost pure stands covering several hundred acres with little understory. Associated species 

include incense cedar and California bay. 

Lower Montane Coniferous Forest. Mixed conifer communities in the Merced Gorge are dominated 

by ponderosa pine and Douglas-fir. This habitat also contains incense cedar, sugar pine, and 

occasional California black oaks. The most common understory shrubs are Mariposa manzanita, 

deerbrush, and bear-clover. Areas where ponderosa pine are the dominant tree species often occur on 

south-facing slopes. Co-dominant species include incense cedar, sugar pine, white fir, California black 

oak, and canyon live oak. Shrubs such as whiteleaf manzanita and mountain whitethorn frequently 

occupy forest openings. Douglas-fir is typically dominant on steep north-facing canyon sides, but 

co-dominants can include white fir, incense cedar, ponderosa pine, and canyon live oak. The 

understory is typically sparse with canopy openings providing habitat for shrubs and perennial herbs. 

Wetlands and Riparian Habitats. As the Merced River cascades through the gorge, the channel 

gradient and bank slopes steepen, the river channel narrows, and the floodplains become considerably 

smaller than those of the Yosemite Valley. Along this stretch of river, the riverbed and banks are 

comprised largely of boulders and cobbles, ranging in size from a few inches to several feet in 

diameter. The steep gradient, combined with the boulders and cobbles of the riverbed and bank, forms 

a series of continuous rapids between Yosemite Valley and El Portal. The Merced Gorge is lined with a 

narrow band of riparian vegetation along the river course. 

Flooding has been an important aspect of the development of riparian communities along the Merced 

River and its tributaries that intersect drier adjacent vegetation types of El Portal. Localized seasonal 

flooding creates debris dams in tributary channels, thus furthering a diversity of scour and 

depositional soils for riparian species. On the Merced River, natural flooding and vegetative patterns 

are influenced by the construction of levees and application of riprap to confine the river. These 

structures have destroyed riparian vegetation and have limited their reestablishment in some places. 

In the El Portal area, riparian communities occur along tributaries of the Merced River, on flat 

topographical shaded terraces above the river, in backwater channels, and in areas where runoff from 

upland sites collects in natural depressions. Native willows, Fremont cottonwood (Populus fremontii 

ssp. fremontii), and Oregon ash (Fraximus latifolia) trees occur in wetter areas, as well as orchard 

components in some locations. Foothill pines and valley oaks tend to dominate the drier terraces 

adjacent to riparian sites. 

Oxbows, river terraces, and seasonal river channels were a part of the riparian wetlands of the area, but 

have been affected by early to mid-20th century development in what is now the El Portal 

Administrative Site. Many of the sites that would be characterized as palustrine have been affected to 

some degree. For example, the wetland near Odger’s Pond and the Abbieville wetland appear to 
Analysis Topics: Natural Resources 

Vegetation and Wetlands 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-215

consist of oxbows or backwater channels that were cut off from hydrologic flows of the main stem of 

the Merced River during construction of Highway 140 in the 1920s (ESA 2004a). These areas continue 

to maintain palustrine wetland characteristics and riparian vegetation. They are likely connected to the 

Merced River in the underground water table and not through surface flows. The remaining wetland 

areas that appear on the USFWS (1995) wetland inventory are riverine perennial wetlands and are in 

proximity to the Merced River or other stream drainages. Direct human intrusion into the riparian 

areas of this river zone, especially to the south, is minimal because of the topography and difficulty of 

access. 

Segments 5 and 8: South Fork Merced River Above and Below Wawona 

These segments include nearly a full range of environments typical to the Sierra Nevada. Vegetation 

zones along the upper South Fork Merced River (Segment 5) include the alpine, subalpine, upper 

montane forest, and lower montane forest zones. Vegetation in the upper South Fork Merced River is 

classified into six broad vegetation types: meadow, chaparral, lower montane broadleaf forest, lower 

montane coniferous forest, upper montane coniferous forest and subalpine coniferous forest. There 

are also areas categorized as barren, which include talus slopes, permanents snowfields, boulder fields, 

rock outcrops, and other unvegetated areas. 

Vegetation zones along the lower South Fork Merced River (Segment 8) include the lower montane 

forest and foothill-woodland zones. Vegetation in the lower South Fork Merced River is classified into 

three broad vegetation types: chaparral, lower montane broadleaf forest, and lower montane 

coniferous forest. These segments of the river are designated as Wilderness. 

As mentioned above, even though riparian and wetland areas are not classified independently under 

the eight broad vegetation types used in the parkwide vegetation map, they are discussed in depth in 

the “Wetland and Riparian Habitats” section below. 

Meadow Plant Communities. Meadow plant communities along the upper South Fork Merced River 

(Segment 5) range from small, isolated alpine meadows at high elevations to moderately sized 

meadows along the river corridor. Alpine and subalpine meadows along the South Fork Merced River 

are similar in composition to those described for the upper Merced River zone (Segment 1). The lower 

South Fork (Segment 8) does not support meadow communities. 

Chaparral Communities. Alpine and subalpine chaparral communities along the upper South Fork 

Merced River are similar in composition to those described for the upper Merced River zone 

(Segment 1). Steeper canyon slopes above the upper South Fork Merced River, as well as the steep 

canyon slopes along the South Fork Merced River below Wawona, are dominated by montane 

chaparral, which contain a variety of manzanitas, ceanothus species such as buckbrush and deerbrush, 

chinquapin, mountain mahogany, huckleberry oak, and interior live oak. 

Lower Montane Broadleaf Forest. Lower montane broadleaf forests along the upper South Fork 

Merced River are similar in composition to those described for the upper Merced River zone 

(Segment 1), although these communities are more widespread in Segment 5, especially toward the 

lower elevations of this segment. Similarly, lower montane broadleaf forests along Segment 8 are 

comparable to those discussed for Segments 3 and 4. 
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Coniferous Forest Communities. Coniferous forest communities along the upper South Fork 

Merced River are classified as subalpine, upper montane, and lower montane. Coniferous forests along 

the upper South Fork Merced River are rich in species (both over and understory) and are comparable 

in conditions to the forest communities described as occurring above Little Yosemite Valley within the 

upper Merced River (Segment 1). High elevations are dominated by whitebark pine, lodgepole pine, 

red fir, and aspen. The upper reaches of the canyon are narrow. The forest is relatively sparse through 

this zone, with most trees and forest species occurring along joints or gaps in the granite. Ponderosa 

pine and Douglas-fir are dominant at lower elevations along Segment 8, with incense cedar, sugar pine, 

and California black oak occurring as sub-dominants. The characteristics of the coniferous forests 

along the lower South Fork Merced River are similar to those in Segments 3 and 4. 

Wetlands and Riparian Habitats. From its headwaters, the South Fork Merced River flows west at a 

relatively consistent but steep gradient through a glaciated alpine environment and then enters a Vshaped, unglaciated river valley. The upper South Fork Merced River supports limited riparian 

vegetation, primarily due to steep topography and high-velocity flows. The steep gradients along the 

upper and lower South Fork Merced River are not conducive to the establishment of an extensive 

riparian zone. Typical riparian species — willow, alder, aspen, and maple — are restricted to a narrow 

fringe along the river. High-elevation tributaries to the South Fork Merced River are either 

unvegetated, high-velocity, and rocky in nature or are only sparsely vegetated. Subalpine meadows 

along the South Fork Merced River are similar in composition to those described for the upper main 

stem of the Merced River. Vegetation in alpine lakes is typically limited to rooted aquatic grasses, 

floating vascular plants, and algae. The upper South Fork Merced River is generally pristine and 

remains virtually undisturbed by human-related effects. The steep gradient below Wawona along the 

South Fork Merced River prevents the establishment of an extensive riparian zone. The limited 

riparian vegetation along the lower reach remains relatively untouched by human intrusion. The 

riverbed and banks are largely composed of boulders and cobbles. 

Segments 6 and 7: Wawona – Vegetation 

Major vegetation zones in the central South Fork Merced River (Wawona) include the upper montane 

forest and lower montane forest zones. Vegetation in the central South Fork Merced River is classified 

into four broad categories: meadow, chaparral, lower montane broadleaf forest, and lower montane 

coniferous forest. As mentioned above (see Merced River Wetlands and Riparian Vegetation), even 

though riparian and wetland areas are not classified independently under the eight broad vegetation 

types used in the parkwide vegetation map, they are discussed in depth in the “Wetland and Riparian 

Habitats” section below. 

Meadow Plant Communities. Wawona Meadow is an approximately 200-acre low-elevation meadow, 

the largest such meadow in Yosemite National Park. Unlike most low-elevation meadows in the park, 

conifer encroachment in Wawona Meadow is minimal. 44 acres of the lower portion of Wawona 

Meadow lies in the Merced River corridor and was converted into a nine-hole golf course in 1918. This 

area continues to be maintained as a golf course and also serves as a sprayfield for reclaimed water. 

Human alterations in the upper portion of the meadow include the construction of ditches in 1936 that 

dewater the meadow. The NPS is presently completing an ecological restoration project to fill these 

ditches and restore natural hydrology. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-217

Chaparral Communities. Chaparral along the central South Fork Merced River (Wawona) is very 

limited and consists of small patches on south-facing, steep canyon walls above the north bank of the 

river. These patches are comprised of birchleaf mountain mahogany (Cercocarpus betuloides), 

buckbrush, and whiteleaf manzanita. The metamorphic rock formation that crosses the South Fork 

Merced River downstream of Wawona is home to several species of plants that are both rare and 

apparently specific to this substrate type. This same formation crosses the main stem of the Merced 

River at El Portal, and also is home to rare plant species, including state-listed ones (Allium 

yosemitense, Lewisia congdonii, Eriophyllum congdonii), in the vicinity of the river. 

Coniferous and Broadleaf Forest Communities. Forest communities in the Wawona area include 

lower montane coniferous and deciduous forests. Humans have affected parts of Segment 6 and 7 

since the turn of the century, and this has affected forest health and composition. Ponderosa pine is 

dominant in the Wawona area, with incense cedar, sugar pine, and California black oak occurring as 

sub-dominants. The understory is composed of shrub species such as manzanita, deerbrush, and bearclover. This community is naturally adapted to frequent low-intensity fires; however, 100 years of fire 

suppression has resulted in a change from an open forest to dense thickets of trees in many areas. 

Under natural conditions, the fire return interval is estimated at 8–12 years (NPS 1990). Present 

conditions can generate fires of much greater severity than those under a natural fire regime. Fire 

management in Segment 7 is complicated by the numerous residences, private lands, and historic 

structures located within the Wawona segment of the corridor. 

Wetlands and Riparian Habitats. In the Wawona area, Big Creek meanders through Wawona 

Meadow before reaching the South Fork Merced River. Wawona Meadow is a large floodplain 

meadow (part of a shallow alluvial valley) and has substantial gravel bars within the channel. In the 

portions where the gradient is gentlest, riparian vegetation (willows and alders) becomes more 

prevalent. Willows often colonize sandbars that are deposited at the margins of or within the river 

channel. In this area, the riparian corridor resembles the riparian corridor seen along the Merced 

River as it flows through Yosemite Valley. As with certain points within Yosemite Valley, trampling of 

riparian vegetation and associated erosion does occur in this area, resulting from heavy use in the 

vicinity of Wawona and the Wawona Campground. 

Also found in this area is Sierra sweet bay (Myrica hartwegii), a shrub endemic to the Sierra Nevada. In 

Yosemite National Park, Sierra sweet bay is found at the average high water line of the South Fork 

Merced River downstream from Wawona and along Big Creek, a tributary to the South Fork Merced 

River (NPS 2012a). Portions of two sizeable populations of Sierra sweet bay occur in the park, one on 

the South Fork of the Tuolumne River and one on Big Creek and on the South Fork Merced River 

below the mouth of Big Creek. Both populations have been documented with herbarium specimens 

over the past 100 years. The NPS (2002) considers Sierra sweet bay a sensitive species, and the 

California Native Plant Society (CNPS Rank 4.3) identifies the plant as being of limited distribution. 

For these reasons, this rare plant has been identified as contributing to the river’s biological ORV. 

Sierra sweet bay is discussed in depth in the “Special Status Species” section. 
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9-218 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Environmental Consequences Methodology 

Proposed management actions under each alternative are evaluated in terms of the context, intensity, 

and duration of the impacts, as defined below, and whether the impacts are considered beneficial or 

adverse to the natural environment. Generally, the methodology for natural resource impact 

assessment follows direction provided in the Council of Environmental Quality Regulations for 

Implementing the National Environmental Protection Act, section 1508.27. 

This impact assessment considers the potential effects that implementation of the Merced Wild and 

Scenic River Comprehensive Management Plan could have on vegetation and wetland resources. 

Vegetation data in the project area derives from the Yosemite Parkwide Vegetation Map (1997) and 

other studies, including the 2010 Assessment of Meadows in the Merced River Corridor, Yosemite 

National Park (Ballenger et al. 2011), the Merced River and Riparian Vegetation Assessment 

(Cardno/Entrix 2011), and the Status of Rare Plants in the Merced River Corridor within Yosemite 

National Park (Colwell and Taylor 2011). Wetland data in the project area derives from site-specific 

wetland delineations associated with past projects, and National Wetland Inventory data (USFWS 

1995) supplemented with the Yosemite Parkwide Vegetation Map (1997) and other studies. Data on 

riparian habitats are taken from the Merced River and Riparian Vegetation Assessment (NPS 2011) for 

the Merced River corridor through Yosemite Valley. Data from the Yosemite Parkwide Vegetation 

Map (1997) are used to describe riparian habitats outside of Yosemite Valley. Quantitative analysis was 

used wherever possible; however, when quantitative analysis is not feasible, qualitative analysis is used. 

Qualitative analysis relies substantially on professional judgment, supported by extrapolation of 

relevant research, where appropriate, to reach reasonable conclusions as to the context, intensity, 

duration, and type of potential impact. 

 Context. The context of the impact considers whether the impact would be local, segmentwide, 

parkwide, or regional. For the purposes of this analysis, local impacts would be those that occur 

in a specific area within a segment of the river. This analysis further identifies whether there are 

local impacts in multiple segments. Segmentwide impacts would consist of a number of local 

impacts within a single segment, or larger scale impacts that would affect the segment as a whole. 

Parkwide impacts would extend beyond the river corridor and the project area within Yosemite 

National Park. Regional impacts would be those that extend to the Sierra Nevada. 

 Intensity. Three primary measures are used to evaluate the intensity of impacts on vegetation 

and wetlands: the size and type of resource, the integrity and condition of the resource, and 

the connectivity of the area to adjacent habitats. The greater the size of a resource, and the 

strength of its linkages with neighboring communities, the more valuable a resource becomes 

to the integrity and maintenance of biotic processes. These measures are used to describe both 

beneficial and adverse impacts. 

The intensity of an impact on vegetation is a measure of perceptible changes in native plant 

community size, continuity, or integrity. Impact intensity is characterized as negligible, minor, 

moderate, or major. Negligible impacts are those that would have no measurable or 

perceptible changes in native plant community size, continuity, or integrity. Minor impacts 

would be measurable or perceptible, but would be localized within an isolated area, and the 

overall viability of the native plant community would not be affected. Moderate impacts would 

cause a measurable and perceptible change in the native plant community (e.g., size, 

continuity, or integrity); however, the impact would remain localized and could be reversed. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-219

Major impacts would be substantial and highly noticeable and could be permanent in their 

effects on native plant community size, diversity, continuity, or integrity. Impacts on 

vegetation are quantified where possible by determining the acreage of vegetation 

communities altered. The amount of each vegetation community that would be directly 

affected is determined by a comparative analysis of vegetation spatial data representing 

existing conditions and conditions under proposed management actions. Other potential 

direct and indirect effects to vegetation communities, such as loss of integrity or vulnerability 

to invasion by nonnative species, are analyzed qualitatively. 

 Duration. The duration of an impact is the time required for native plant communities to 

recover from the implementation of an alternative. The duration of impact is characterized as 

short-term or long-term. A short-term impact would have an immediate effect on the size, 

continuity, or integrity of native plant communities and is usually associated with transitional 

types of activities, such as facility construction. In general, short-term impacts on vegetation are 

those that would last up to 20 years following implementation of an alternative. Long-term 

impacts would lead to a loss in the size, continuity, or integrity of native plant communities. In 

general, long-term impacts would last longer than 20 years after implementation of an 

alternative. 

 Type of Impact. Impacts are considered adverse if implementation of an alternative would 

reduce the size, continuity, or integrity of a native plant community. Impacts are considered 

beneficial if implementation of an alternative would increase the size, continuity, or integrity 

of a native plant community. 

Environmental Consequences of Alternative 1 (No Action) 

All River Segments 

The following discussion provides an overview of the types of impacts on vegetation and wetland 

resources that would occur in all segments of the Merced River corridor under Alternative 1(No 

Action). The No Action Alternative would be a continuation of current conditions and management. 

Wetlands are afforded special protection under Executive Order 11990 (“Protection of Wetlands”) 

and NPS Director’s Order 77-1 (“Wetland Protection”). The NPS must avoid direct or indirect adverse 

impacts on wetlands or, where impacts cannot be avoided, minimize loss or degradation by every 

practicable effort. The CWA and Rivers and Harbors Act, as regulated by the Corps and the 

U.S. Environmental Protection Agency, govern actions that may reduce or degrade wetlands. In 

general, these regulations and associated management actions would continue to maintain existing 

wetland conditions throughout Segments 1–8, and lead to no net loss of wetlands. Some local 

beneficial impacts would occur under current management practices that protect or enhance existing 

wetlands. 

All riprap and abandoned infrastructure within the Merced River channel and meadow floodplains 

would remain, which may continue to alter the free-flowing condition of the river and constrain the 

river from naturally migrating and changing course. This infrastructure includes remnants of former 

sewer treatment facilities, sewer and water lines, man-holes, and former bridge abutments, Although 

some large wood would remain in place within the river channel, the NPS would continue to remove 

large wood where there are threats to human safety or infrastructure. This action would continue to 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-220 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

influence habitat characteristics within the channel, such as riffle/pool complexes, cover for aquatic 

species, and stability of riverbanks. 

The NPS would continue to implement ecological restoration projects identified in the 2009 Settlement 

Agreement and projects that qualify as a Categorical Exclusion under NEPA. The NPS would also 

continue to control invasive species as prescribed in the Invasive Plant Management Plan and Update

(NPS 2010, 2008), as well as removing encroaching conifers from some meadows. These actions would 

increase habitat integrity by decreasing the presence of invasive plants and enhancing habitat quality 

for terrestrial and aquatic wildlife. Current actions under the No Action Alternative to enhance 

biological values would result in long-term, minor, beneficial effects for vegetation and wetlands 

throughout the Merced River corridor. 

The No Action Alternative would perpetuate the kinds and amounts of use that exist today. No new 

structures would be constructed in the river corridor with the exception of minor structures that are 

small; temporary; easily removed; not habitable; designed to support existing uses, systems, and 

programs; located within the existing building footprint; and not created solely for commercial 

purposes. Temporary housing structures for employees displaced by the 2008 rockfall would remain in 

place as needed. Housing for NPS employees and park partner staff would remain in current locations 

and at current levels. 

Many resource impacts deriving from visitor and administrative use in Segments 1–8 would remain. 

Informal trails, bike paths, campsites, roads, bridle paths, parking, staging areas, and trails would 

remain in sensitive areas such as meadows and riparian habitat. Traffic congestion, lack of parking 

spaces, and improper parking adjacent to or encroaching on the edges of meadows would continue to 

affect meadow habitat. Adverse impacts would be mitigated through continuation of current policies, 

including visitor education with an emphasis on Leave-No-Trace practices in Wilderness, and 

restrictions on amounts and locations of overnight use. Current visitor use and facility management 

actions under the No Action Alternative would result in long-term, minor, adverse impacts on 

vegetation and wetlands throughout the Merced River corridor. 

Segment 1: Merced River above Nevada Fall 

Continuation of current wilderness management policies, including protection of natural process, 

visitor education with an emphasis on Leave-No-Trace practices, and restrictions on amounts and 

locations of overnight use, would continue to protect vegetation and wetland resources in Wilderness 

segments of the Merced River corridor. In general, adverse impacts on vegetation and wetland 

resources in Segment 1 under the No Action Alternative would be local, long-term, and minor. 

Vegetation and wetlands of the upper Merced River is generally intact, except where visitor use is 

intense (e.g., in the vicinity of the Little Yosemite Valley Backpackers Campground, Moraine Dome 

Backpackers Campground, Merced Lake High Sierra Camp and Backpackers Campground, and along 

major trail routes). 

Local, adverse impacts on native meadow plant communities associated with stock traffic would 

continue. Types of adverse effects associated with continued stock use include the spread of noxious 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 1 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-221

weeds, as well as grazing, trampling, compaction, and erosion. These effects would result in some 

localized losses in the natural structure, diversity, and productivity of meadow and riparian habitats. 

The Merced Lake—East Meadow would continue to exhibit very low vegetation cover and high bare 

ground levels associated with high levels of administrative stock use (Ballenger et al. 2011). Adverse 

impacts on meadow plant communities associated with stock use would be local, long-term, and minor 

within Segment 1. 

The degree to which vegetation communities would be affected under the No Action Alternative 

depends on the position of the community relative to existing infrastructure and visitor use, as well as 

its sensitivity to perturbation. Chaparral and forest communities in proximity to Merced Lake High 

Sierra Camp and Merced Lake Backpackers Campground, Little Yosemite Valley Backpackers 

Campground, Moraine Dome Backpackers Campground, and major trail routes would experience 

site-specific, long-term, minor adverse effects. In other areas of the upper main stem of the Merced 

River, continued use of existing facilities (e.g., trails) at a similar level of intensity would have negligible 

effects on vegetation. 

Ongoing visitor use in localized areas of Segment 1, including near the Little Yosemite Valley 

Backpackers Campground, Moraine Dome Backpackers Campground, and Merced Lake High Sierra 

Camp and Merced Lake Backpackers Campground would continue to have an adverse effect on the 

integrity of some wet meadows in or adjacent to these areas. This includes local and minor adverse 

direct and indirect impacts on wet meadows and aquatic habitats from trampling, compaction, and 

erosion. Existing trails in some areas, such as the wet meadow complex surrounding Merced Lake, 

would also continue to adversely affect wetland and aquatic habitats through habitat fragmentation 

and by acting as barriers to localized plant and wildlife movements (barriers, in turn, affect seed 

sources, nutrients, and plant distribution patterns). Visitor use may create informal trails, which can 

fragment habitat, compact soil, and potentially disrupt hydrologic processes. Informal trails would 

remain in the wet meadow complex surrounding Merced Lake, Doc Moyle’s Meadow, and Washburn 

Lake Meadow. Ongoing visitor use also would continue to contribute to the introduction or spread of 

noxious weeds. These ongoing and future adverse impacts would be long-term, and minor within 

localized areas of Segment 1. 

Segment 2: Yosemite Valley 

Under the No Action Alternative, the size, structure, productivity, and continuity of vegetation and 

wetlands within Yosemite Valley (Segment 2) would continue to be affected by existing infrastructure 

and visitor use. General human-related effects in Segment 2 include trampling, unintentional 

introduction and spread of nonnative species (both plants and wildlife), litter, erosion, and 

compaction. Visitor use would continue to adversely affect vegetation and wetlands in areas of high 

use by compacting soils, reducing vegetative cover, altering streambanks, and inducing erosion. 

Modifications to the river channel and floodplain (through soil compaction, loss of riparian 

vegetation, and accelerated erosion) influence important stream characteristics that may combine to 

accelerate widening of the Merced River, which in turn would affect vegetation patterns over time. 

Trampling and visitor use would also continue to adversely affect understory vegetation, introduce 

and spread nonnative species, and impede natural regeneration of native oaks, woody shrubs, and 

riparian and meadow vegetation in localized high use areas. Development may limit the size or 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-222 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

fragment species populations locally. The east Valley is highly developed and development has 

resulted in disconnected vegetation communities. Under the No Action Alternative, these vegetation 

communities would remain in their fragmented state. 

Meadow size would continue to gradually decrease in most meadows in Segment 2 due to conifer 

encroachment and existing alterations to natural meadow hydrology. Existing infrastructure, such as 

roads, channelized tributaries, bridges, ditches, structures, and campgrounds, would continue to alter 

meadow hydrology, or directly preclude establishment of meadow vegetation. Hydrological 

alterations would continue to influence meadow plant species composition as soil conditions trend 

toward drier conditions. Dry conditions would also sustain and encourage nonnative plant invasion, 

with a resulting loss of native diversity and productivity, as most non-native meadow species are 

currently found in drier areas. Ongoing meadow maintenance activities, including the removal of 

encroaching conifers, would offset some of these adverse impacts. Linear features, such as some roads 

and bridges, would continue to disconnect the main Merced River channel from the meadow 

floodplain during minor flood events, and impose unnatural barriers to water movement. 

Informal meadow trails would largely remain under the No Action Alternative. Riparian habitat would 

continue to be protected at the current level. Localized riverbank erosion and scouring associated with 

bridges would remain. Denuded riverbanks in proximity to east Yosemite Valley campgrounds would 

remain, with the exception of riverbank restoration actions at North Pines Campground, which were 

approved in the 2009 Settlement Agreement. Conifer encroachment would be managed with fire 

reintroduction and direct removal of sapling trees at current management levels. Impacts on meadow 

and riparian habitats, including habitat fragmentation, reduced productivity of riparian and adjacent 

aquatic communities, and potential disruption of connectivity between terrestrial and aquatic habitats 

would continue 

Existing infrastructure, such as roads, bridges, ditches, structures, and campgrounds, would continue 

to indirectly affect upland vegetation patterns. For example, landscape irrigation would continue to 

affect native oaks. The development of linear features, such as roads and bridges, may act as unnatural 

barriers to plant colonization. 

Existing infrastructure, such as roads, bridges, and ditches, that is near or adjacent to wetlands and 

riparian habitats would continue to adversely affect some of these features through alterations to the 

floodplain and localized hydrology. These hydrological alterations sometimes result in the conversion 

of wetland and riparian habitats to uplands, and ultimately result in a loss of wet meadow plant species 

and an increase in upland species, including conifer encroachment of wet meadow and riparian 

communities. 

General visitor-related effects in high-use areas include trampling, litter, erosion, soil compaction, and 

the unintentional introduction and spread of nonnative plants and wildlife. Floodplain wetlands and 

the aquatic habitat of the Merced River would be adversely affected by these activities by further 

compacting soils, reducing vegetative cover, altering streambanks, and causing erosion. Ongoing 

activities that contribute toward the modification of the river channel and floodplain (through soil 

compaction, loss of riparian vegetation, the removal of large wood from the river channel, and 

accelerated erosion) influence important stream characteristics such as riffle/pool complexes, 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 1 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-223

substrate type, water quality, channel migration, and riparian and wet meadow cover. Some bridges 

would continue to cause hydrologic stress on upstream and downstream riparian areas. Along some 

stretches of the Merced River in eastern Yosemite Valley, riverbanks are largely denuded, affecting 

shading and nutrient dynamics in aquatic habitats. These effects may combine to accelerate bank 

erosion and widening of the Merced River (i.e., the channel could widen, flatten, and become 

shallower in reaction to the streambank destabilization caused by visitor use and trampling); increase 

water temperature; increase suspended sediment; reduce overbank flooding frequency; and reduce 

dissolved oxygen levels. Such changes to the physical characteristics of the river would be harmful to 

aquatic organisms, as well as riparian and wetland vegetation. These activities are focused in developed 

and high-use areas, particularly in east Yosemite Valley, and therefore tend to be localized. Overall, 

continued visitor-related effects on wetlands and riparian habitats would result in a local, long-term, 

moderate, adverse impact on wetland and riparian habitats within Segment 2. 

Segments 3 and 4: Merced Gorge and El Portal 

Valley oak stands are considered a subset of the foothill woodland. Of particular concern along 

Segment 4 are the valley oaks, a regionally rare species, occurring in the El Portal area. Currently, 

vehicles park under the dripline of the valley oaks. This practice compacts soil under the trees, 

affecting root health, water uptake, and soil aeration. Existing development and trampling in the 

vicinity limits the area where oak seedlings can be recruited. These adverse impacts on valley oaks in 

the El Portal area are considered local, long-term, and moderate. 

Like other river segments, wetlands and riparian resources in Segments 3 and 4 would continue to be 

protected by existing regulations, policies, and management actions. Some wetlands and riparian 

habitats would continue to be adversely affected by existing infrastructure and visitor use. Wetlands 

and riparian habitats in Segments 3 and 4 tend to occur in narrow bands framing the Merced River, 

with several exceptions such as braided river channel at Cascades and west of the park boundary, and 

the El Portal pond. Visitor use within riparian areas of the Merced Gorge is minimal due to steep 

topography. The riparian zone would continue to be affected by infrastructure, including roads and 

pullouts, as well as trampling by visitors accessing the river. Roads, parking lots, and other impervious 

surfaces in or near the corridor would continue to release nonpoint-source pollutants into stormwater 

runoff that could subsequently discharge to the aquatic habitat of the Merced River. Impervious 

surfaces accumulate automobile-related pollutants, refuse, and other nonspecific pollutants that are 

easily transported to adjacent or nearby wetland resources through stormwater runoff. The riparian 

community through the Merced Gorge would continue to be affected by use of El Portal Road (and 

associated pollutants). Odger’s Pond in El Portal is bisected by the Foresta Road and confined by 

Highway 140. The pond’s natural hydrology is adversely affected by the proximity of these roads, 

though it does function as an overflow channel during extremely high floods. These adverse effects are 

considered local, long-term, and minor under the No Action Alternative for Segments 3 and 4. In 

general, adverse impacts on wetlands and aquatic resources in Segments 3 and 4 under the No Action 

Alternative are considered to be local, long-term, and minor. 
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9-224 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Segments 5 and 8: South Fork Merced River Above and Below Wawona 

Adverse effects on vegetation communities located in the upper and lower South Fork Merced River 

are generally associated with visitor and stock use. No development, other than a few trails, currently 

occur in the upper and lower portions of the South Fork Merced River. Access is difficult, and visitor 

and stock use is low. Any increases in visitor use of the upper and lower reaches of the South Fork 

Merced River would negatively affect vegetation by increasing erosion, soil compaction, trampling, 

and refuse; decreasing water quality and vegetative cover; and through the potential introduction of 

nonnative species. However, the intensity of these effects would be negligible over time because 

topography and limited trail access would continue to limit the majority of visitors that could access 

these portions of the South Fork Merced river. Continuation of current Wilderness management 

policies, including protection of natural process, visitor education with an emphasis on Leave-NoTrace practices, and restrictions on amounts and locations of overnight use, would continue to protect 

vegetation and wetland resources in the Wilderness segments of the Merced River corridor. Overall, 

adverse impacts in this segment would be local, long-term, and negligible. 

Segments 6 and 7: Wawona 

Although the upper portion of Wawona Meadow is large and generally intact, the lower meadow has 

been the site of repeated human intrusion since the turn of the century. The lower meadow continues 

to be affected by ditches, a golf course, a sprayfield for reclaimed water, and helicopter staging. Nonnative plants including velvet grass, an aggressive invasive plant, dominate the golf course and provide 

a constant seed source for spread into the upper portions of Wawona Meadow. In addition, the 

continued use of the golf course precludes the area from potentially reverting to wet meadow habitat. 

These uses would remain and would continue to cause local, long-term, major, adverse effects on 

vegetation and wetlands in Wawona Meadow. 

Visitor use would continue to affect additional wetlands and riparian habitat in Segment 7 by 

compacting soils, reducing vegetative cover, altering streambanks, and inducing erosion. For example, 

the proximity of campsites in the Wawona Campground to the South Fork Merced River promotes 

trampling and riverbank erosion, inhibiting vegetation growth. Similarly, the picnic area along 

Wawona Road provides an undesignated river access point, which promotes riparian vegetation 

trampling and moderate erosion. Roads, parking lots, and other impervious surfaces in or near the 

Merced River corridor would continue to release nonpoint-source pollutants into stormwater runoff 

that could subsequently discharge to low-lying wetlands and the aquatic habitat of South Fork Merced 

River. Abandoned metal pipes in South Fork Merced River side channels dewater the floodplain 

terrace, affecting wetland hydrology. Ongoing impacts to habitat due to visitor use and existing 

infrastructure would result in local, long-term, minor, adverse effects on wetland and riparian habitats 

of the central South Fork Merced River and Wawona. 

Summary of the No-action Alternative Impacts 

Existing development and human activity in the Merced River corridor affects vegetation patterns and 

wetland and riparian resources in localized areas. Implementation of the No Action Alternative would 

result in the continued impact on the size, structure, productivity, and continuity of habitats located 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 1 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-225

adjacent to or near existing infrastructure and areas that experience a high degree of visitor use. 

Existing infrastructure would also continue to alter ecosystem processes where they disrupt hydrology 

and act as barriers to species. Visitor use would continue to cause adverse effects, such as trampling, 

erosion, and compaction in localized areas. The combined effects of visitor use and existing 

infrastructure would in some cases lead to alterations in vegetation patterns (e.g., type conversion of 

wet meadow to conifer forest, or vegetated to non-vegetated) and modifications to the Merced River 

channel and floodplain (e.g., channel widening) in localized areas over the long-term. 

Under the No Action Alternative, the NPS would continue to implement existing goals and policies 

under existing regulations (e.g., Executive Order 11990, Director’s Order 77-1, CWA, Rivers and 

Harbors Act) and make incremental improvements to vegetation and wetland conditions on an ad-hoc 

basis, as opportunities and resource problems were presented. For example, constrained by existing 

developments and infrastructure, enhancement and reestablishment of wetlands would continue on a 

site-by-site basis instead of a parkwide or Valley-wide basis. Although substantial piecemeal 

improvements can take place under current direction, “reactive” resource management is not always 

effective at protecting sensitive resources over the long-term. Overall, effects could escalate as time 

passes and the effects on natural vegetative patterns worsened in some areas. These effects would be 

concentrated in areas of high visitor use such as Yosemite Valley, El Portal, and Wawona Meadow at 

the site of the Wawona Golf Course. Overall, long-term, moderate, adverse effects on vegetation and 

wetlands would continue under the No Action Alternative. 

Cumulative Impacts of the No Action Alternative 

Cumulative effects to vegetation and wetlands are based on analysis of past, present, and reasonably 

foreseeable actions in the Sierra Nevada region in combination with potential effects of the No Action 

Alternative. The projects identified below include those projects that have potential to affect local 

vegetation and wetland patterns (i.e., within the Merced River corridor), as well as large-scale or 

regional patterns. The spatial scale of the cumulative analysis for the Vegetation section is the Sierra 

Nevada. 

Past Actions 

Regional vegetation has been historically affected by logging, fire suppression, rangeland clearing, 

grazing, mining, draining, damming, diversions, and the introduction of nonnative species. Portions of 

the Merced River and South Fork Merced River corridors within Yosemite National Park are relatively 

unaltered by many of these past actions, especially in Wilderness areas where use has had little effect on 

vegetation. Development and use of infrastructure within Yosemite Valley and throughout the Sierra 

Nevada have caused long-term, adverse alterations to native vegetation patterns since European 

American occupation. Past restoration actions have reversed the adverse effects of some of these past 

actions, and have also contributed direct beneficial effects on vegetation communities. 

Cumulative impacts on wetland resources are based on analysis of past, present, and reasonably 

foreseeable future actions in the Sierra Nevada in conjunction with the potential effects of 

Alternative 1(No Action). Over half of the wetland area around the globe has been lost, and much of 

remaining wetland area is negatively impacted (Zedler and Kercher 2004). Wetlands are the most 
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9-226 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

altered and impaired habitat of the Sierra Nevada, and, as a small proportion of the landscape, are 

relatively rare (SNEP 1996). Dams, roads, and diversions in the Sierra Nevada have had a profound 

effect on streamflow patterns and wetlands. Broad valleys with wide riparian wetlands were often used 

as reservoir sites. Much of the flatwater on the western slope of the Sierra Nevada below 5,000 feet in 

elevation is artificial. These past actions have had long-term, adverse effects on regional wetland 

habitat. 

Within Yosemite National Park past facility development (construction of dams, diversion walls, 

bridges, roads, pipelines, riprap, recreational use, agriculture, buildings, and campgrounds) and 

associated recreational use reduced extent and function of wetlands and other aquatic resources. Most 

loss of wetland area, such as wetland meadow expanse in Yosemite Valley, took place before the 

1940s. However, most recent past projects have resulted in beneficial impacts on wetland and riparian 

habitats through restoration efforts and invasive plant species control, such as the Cook’s Meadow 

Ecological Restoration Project. 

Dams and diversions throughout most of the Sierra Nevada have profoundly altered stream-flow 

patterns and water temperatures. The removal of dam features can have beneficial impacts by 

restoring function to regional wetlands and riparian habitats. Past examples in Yosemite include the 

removal of Cascades Diversion Dam and Happy Isles Dam. Restoration and management projects may 

have site-specific and short-term, adverse effects (e.g., construction-related effects); however, the 

general goal of these projects is to increase coordinated resource management and to restore sensitive 

ecosystems. Therefore, these projects have a long-term, beneficial, cumulative impact on regional 

wetlands and riparian habitats. 

Past projects and plans that contribute toward a cumulative effect on native plant and wetland 

communities include the following: 

Management and Restoration – South Fork and Merced Wild and Scenic River Implementation 

Plan, Cascades Diversion Dam Removal, Cook’s Meadow Ecological Restoration, Fern Springs 

Restoration, Happy Isles Dam Removal, Happy Isles Fen Habitat Restoration Project, Happy Isles 

Gauging Station Bridge Removal, Merced River Ecological Restoration at Eagle Creek Project 

Present Actions 

Present development projects are not located within sensitive vegetation and wetland communities 

and incorporate measures to ensure the protection of any sensitive resources. Adverse impacts from 

present development actions are similar to those discussed for past actions. In general, the utility 

improvement projects include long-term improvements through the relocation of utilities outside 

sensitive areas, though construction of new utility lines under roads could influence subsurface 

drainage patterns. Current facility-related projects and plans that contribute toward a cumulative 

effect on native plant communities include the following: 

Facility Development – Crane Flat Utilities, East Yosemite Valley Utilities Improvement 

Plan/Environmental Assessment, Wahhoga Indian Cultural Center, Parkwide Communication Data 

Network, South Entrance Station Kiosk Replacement, Tioga Road Rehabilitation 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 1 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-227

Beneficial impacts for present management and restoration actions are similar to those discussed for 

past actions. Specific examples of present projects and plans with beneficial effects include the 

following: 

Management and Restoration – Yosemite Vegetation Management Plan, General Ecological 

Restoration, 2004 Fire Management Plan/EIS, Fuels reductions/forest rehabilitation projects 

(USFS), Tuolumne Wild and Scenic River Comprehensive Management Plan

Reasonably Foreseeable Future Actions 

Adverse impacts resulting from reasonably foreseeable development in the future are limited, as little is 

planned. Increasing numbers of visitors would perpetuate and potentially increase adverse impacts 

where wetlands vegetation communities are near areas currently used for recreation. Beneficial 

impacts for reasonably foreseeable future actions are similar to those discussed for past actions. 

Specific examples of reasonably foreseeable future projects include the following: 

 Changing demographics of visitors in Yosemite 

 Climate change 

 Concessioner Parking Lot Restoration 

 Restoration of the Mariposa Grove Ecosystem 

 Yosemite Wilderness Stewardship Plan/EIS 

Overall Cumulative Impacts 

Cumulative adverse effects would be related to increased development and access. Many of the 

aforementioned projects has the potential to have substantial site-specific adverse effects on vegetation 

resources during construction (short-term) and by direct displacement of resources (long-term). The 

larger effect of these actions is related to population and regional growth and their subsequent effect on 

natural resources, including native vegetation patterns. Examples of construction-related and humanuse-related effects on vegetation patterns include direct displacement of vegetation (e.g., replaced with 

structures); introduction of nonnative species that invade adjacent natural areas and displace native 

species (e.g., spread by construction equipment and materials, vehicles, grazing animals, or backyard 

gardening); fragmentation of habitats, which decreases genetic diversity; alteration of natural patterns 

(e.g., fire suppression around structures, the introduction of night light); and increased erosion and 

sedimentation (e.g., during grading activities, overuse of trails). In total, regional development and 

growth could have a net long-term, major, adverse effect on regional vegetation resources that would not 

be compensated by regional planning or restoration projects discussed above. 

Wetland and riparian systems of the Merced River have been substantially altered by development and 

visitor activities. These changes have negatively influenced wetland size, form, and function and the 

plants, wildlife, and aquatic species that inhabit them. Restoration projects and management plans to 

help restore ecosystem function have lessened impacts in some areas, and have also resulted in 

beneficial effects. With increased visitor demand, it is anticipated that long-term, minor to major, 

cumulative, adverse impacts on wetlands would occur adjacent to areas where visitor use is 

concentrated. Existing facilities that encroach on historic wetlands limits the potential for ecosystem-
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-228 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

scale restoration projects. In addition, the intrusion of conifers in wet meadows would eventually 

reduce the size and overall amount of wetland habitats in Yosemite National Park. However, the 

quality of wetlands would improve as a result of individual restoration projects. 

Past impacts on wetlands in the Sierra Nevada have been long-term, adverse, and major. Present and 

foreseeable future actions would contribute to reversing the major adverse impacts of past actions in 

Sierra Nevada, and would produce long-term, minor, beneficial effects on wetlands. For example, the 

Tuolumne Wild and Scenic River Comprehensive Management Plan is expected to produce longterm, beneficial effects on wetlands and riparian habitats in the region. These past, present, and future 

effects, in conjunction with the local, long-term, minor, adverse impacts of Alternative 1, would result 

in long-term, minor, adverse, impacts on wetlands. 

Environmental Consequences of Actions Common to Alternatives 2–6 

As discussed in the “Environmental Consequences Methodology” section, ecological restoration 

activities may cause some local, short-term, minor, adverse impacts, but ultimately would result in 

beneficial impacts as natural ecological processes are restored. For example, construction activities 

associated with restoration management actions could have local, short-term, minor, adverse impacts 

on plant communities. Potential adverse impacts on vegetation include damage to or removal of 

vegetation, and the potential introduction and spread of invasive nonnative species. Vegetation that is 

removed would not substantially fragment existing native vegetation communities, reduce species 

diversity, or substantially reduce the overall size or quality of native plant communities along the 

Merced River corridor. These local, short-term, minor, adverse impacts from implementation of 

restoration management actions are not discussed further under each individual restoration action. 

River Segments 1–8 

Impacts of Actions to Protect and Enhance River Values 

Biological Resource Actions. The following discussion provides an overview of the types of impacts 

to vegetation resources that would be common to all segments under all action alternatives. All action 

alternatives include programmatic restorative management actions that would occur across all 

segments of the Merced River Corridor. Program level actions include the removal of underground 

infrastructure, removal of riprap, and the management of large wood. In order to improve the 

hydrologic function and restore ecological integrity, the NPS would remove abandoned underground 

infrastructure throughout the corridor. This infrastructure currently contributes to dewatering of 

meadows and wetlands, and alteration of the natural hydrologic regime of the Merced River. Removal 

of these facilities would have a corridorwide, long-term, moderate, beneficial impact on meadow, 

riparian, and wetland habitats. The park would implement bioengineered riverbank stabilization 

techniques and selective large wood management as appropriate to support riverbank stabilization and 

improve aquatic habitat complexity. All areas from which infrastructure and riprap are removed would 

be returned to natural conditions, including revegetating with appropriate native plants. Removal of 

this infrastructure and riprap would result in a corridorwide, long-term, moderate, beneficial impact 

on riparian plant communities. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Common to Alternatives 2–6 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-229

Program level actions include the protection of the riparian zone from new development within 

150 feet of the ordinary high water mark and the removal of campsites from within 100 feet of the 

ordinary high-water mark. The NPS would undertake certain measures to address ongoing vegetation 

impacts, including those resulting from unauthorized river access points, informal trails, and conifer 

encroachment into meadow areas, through various restoration techniques, fencing and area closures, 

and visitor education and visual cues. Toward that end, the park would utilize brochures, maps, 

signage, and improved trail delineation techniques to direct visitors away from sensitive areas. These 

programmatic restoration management actions would improve hydrologic function and restore 

ecological integrity of the Merced River corridor and associated plant communities and wetlands, 

address ongoing and future impacts on park resources and infrastructure, and manage visitor use and 

development along the river corridor. Removing abandoned underground infrastructure, restoring 

informal trails, removing conifers from meadows, directing visitor use, removing riprap, and restoring 

free-flowing conditions along the Merced River corridor would be part of a comprehensive strategy to 

reduce existing adverse impacts on meadow and riparian vegetation. Thus, these management 

measures would have a corridorwide, long-term, moderate, beneficial impact on plant communities 

and wetlands along the corridor 

Hydrologic/Geologic Resource Actions. Specific projects to protect and enhance the river’s 

hydrologic and geologic values that would occur across all segments under Alternatives 2-6 include 

removing 3,400 feet of riprap from the river bank and revegetating with riparian species, and replacing 

an additional 2,300 feet of riprap with bioengineered riverbank stabilization devices. Riprap placed 

along the banks of the Merced River inhibits the establishment of riparian vegetation. The removal of 

riprap and subsequent restoration of riparian habitat would result in a corridorwide, long-term, 

moderate, beneficial impact on native riparian plant communities. 

Segment 1: Merced River above Nevada Fall 

Impacts of Actions to Protect and Enhance River Values 

Ecological restoration actions that would occur within Segment 1 under actions common to 

Alternatives 2–6 include measures to reduce impacts on plant communities. Under Alternatives 2-6, 

trails in Segment 1 would be rerouted out of wetlands and sensitive communities. New trail routes 

would avoid wetlands and sensitive habitats. Under Alternatives 2-6, the park would relocate sections 

of trail through wetlands in Echo Valley and mineral spring outflow between Merced Lake and 

Washburn Lake to less sensitive areas. The trail along wet sections of the Mist Trail would be 

hardened to avoid trail widening. Formal trails through meadows along the Triple Creek Fork cause 

extensive rutting and head cutting and would be rerouted to upland habitats, where possible. Informal 

trails in the Merced Lake Shore Meadow, adjacent to the Merced Lake High Sierra Camp, fragment 

meadow plant communities, stunt vegetation lining the lake shore, interrupt meadow hydrology, and 

compact soils. Under Alternatives 2-6, the park would decompact soils along informal trails at the 

Merced Lake Shore Meadow, fill ruts with native soils, and revegetate denuded areas with native 

plants. Merced Lake East Meadow near the Merced Lake Ranger Station has high levels of pack stock 

use, associated with lower vegetation cover and higher levels of bare ground. Overall, these actions 

would result in a segmentwide, long-term, moderate, beneficial impact on plant communities and 

wetlands in Segment 1. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-230 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Segment 2: Yosemite Valley 

Impacts of Actions to Protect and Enhance River Values 

Actions to protect and enhance river values that would occur in Yosemite Valley under Alternatives 2-6 

involve removal of abandoned infrastructure and other development affecting the Merced River’s 

hydrologic function, extensive meadow restoration, and management of high visitor-use areas to address 

associated impacts on riparian habitats. The park would also restore six miles of informal trails in 

Yosemite Valley meadows. Removal of abandoned or obsolete infrastructures would reduce ongoing 

impacts on meadow hydrology and lessen channel scour. Upland restoration activities, including 

removal of informal trails, roadbeds, and parking areas, would improve meadow health. Habitat 

restoration actions in Segment 2 common to Alternatives 2-6 are displayed in figures 9-13 through 9-16. 

The types of habitat that would be affected by these restoration actions in Segment 2, as well as the types 

of habitat that would be enhanced or restored, are summarized in tables 9-6 and 9-7. A total of 151 acres 

of vegetation would be enhanced or restored in Segment 2, including 35.84 acres of wetlands. 

Meadow restoration would include actions to improve hydrologic function, restore native vegetation, 

and remove inappropriate uses or facilities. Meadow habitat integrity, extent, and hydrological 

connectivity to the river would be enhanced through construction of wide box culverts (or other 

design components such as rolling dips, permeable subgrade, etc.), formalizing or removing shoulder 

parking, restoring natural topography, removing ditches and abandoned infrastructure, and improving 

roadways and trails. In addition, the NPS would decompact soils and revegetate denuded meadow and 

riparian habitat. Specific management actions would include filling ditches, removing encroaching 

conifers, relocating and/or elevating trails onto boardwalks, revegetation with willows and other native 

species, removing abandoned infrastructure, removal and restoration of informal trails and parking 

areas, decompacting soils, and improving road crossings in meadows. Overall these measures would 

improve the hydrologic function and restore the ecological integrity of Yosemite Valley meadows. 

Programmatic actions also include improving the condition of plant communities at specific locations 

in Yosemite Valley (targeted 67 potential acres) by restoring the mosaic of meadow, riparian 

deciduous vegetation, black oak, and open mixed conifer forest. Management actions may include 

re-vegetation, prescribed fire, mechanical removal of conifers, and re-design of infrastructure. These 

actions will enhance the condition of the Merced River ecosystem by sustaining the diverse mosaic of 

interconnected plant communities. 

Programmatic restorative management actions to improve the free-flowing condition of the river that 

would occur within Segment 2 under all action alternatives include in channel improvements, such as 

strategically placing large wood (log jams) to lessen the scouring from bridge structures. In the river 

reach upstream of the El Capitan moraine to the Sentinel picnic area, localized restoration would 

enhance channel complexity. Water quality would be improved by relocating the Upper Pines Dump 

Station. These actions would result in enhanced channel free flow, increased channel complexity, 

increased streambank stability, and restored riparian habitat segmentwide. Overall these measures 

would improve the free-flowing condition of the river and restore the ecological integrity of Yosemite 

Valley riparian habitats. 
North Pines

Campground

Royal Arch Creek

wahnee Bike Path

Stoneman

Bridge

Lower Pines

Campground

Stoneman

Meadow

Clark's

Bridge

Backpackers

Campground

Ahwahnee

Bridge

Sugar Pine

Bridge

p Trail

Ahwahnee Hotel

Historic Landmark

Staircase

Falls

Upper Pines

Campground

Housekeeping

Camp

Camp Curry Village

Stock

Bridge

Housekeeping

Camp Bridge

Sou hs t

di e Dr vi e

LeConte Memorial Lodge

Historic Landmark

Merced RIver

Northside Drive

de Drive

Ahwahnee

Meadow

Washington

Column

Stables Area

Existing Vegetation 

Surfaced Area

Barren

Lower Montan

Lower Montan

Meadow

Water

Retain Building

Campground

Recreational S

SOURCE: NPS, 1997, 2011, 2012
Bridge

Sentinel

Merced River

Lost Arrow Drive

Lost Arrow Drive

Village Drive

Housekeeping

Camp

Superintendent's

Bridge

Sentinel Boardwalk

Norths di e Drive

Northside Drive

Rangers' Club

Historic Landmark

Chapel

Yosemite Valley

T

Yosemite Village

Southside Drive

Oak Lane

Sentinel Crossover

Tecoya Road

Tenaya Way

Camp 6 Road

Cedar Lane

a C st

Cel fil Cf r uo t

Bou dl

er L

na

e

Ahwahnee Road

Meadow

Cook's

Meadow

Ahwahnee

Meadow

Sentinel

Existing Vegetation a

Recreational Se

Retain Building

Water

Meadow

Lower Montane 

Lower Montane 

Barren

Surfaced Area

Yo

SOURCE: NPS, 1997, 2011, 2012

0 0.125 0.25

Miles

Map Area

Segment

4

Segment

3

Segment

2 Segment

1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment
Camp 4

Historic Site

Yosemite Lodge

Sentinel

Beach

Leidig

Meadow

Swinging

Bridge

Yosemite Lodge Road

Nor ht s di e Dr vi e

Sou 

Wahhoga

Merced RIver

Sentinel Beach

Picnic Area

Swinging Bridge

Picnic Area

Lower Yosemite

Fall Picnic Area Existing Vegetation and Infrastructure

Surfaced Area

Barren

Lower Montane Broadleaf

Lower Montane Needleleaf

Meadow

Water

Retain Building

Recreational Segment Corridor Classification

Habitat Restoration Actions

River Access

Remove Building

Black Oak Restoration

Meadow Restoration

Riparian Restoration

Riparian and Floodplain Restoration

Road mitigation

Boardwalk

Remove informal trail

New fencing

No Action for riprap

Keep riprap and plant

Remove riprap and bioengineer

Remove riprap and revegetate

Y

SOURCE: NPS, 1997, 2011, 2012
Cathedral Beac

Bridge

El Capitan

Pohono

Bridge

UV140

|ÿ41

Northside Drive

El

Capitan

Leaning

Tower

Cathedral

Rocks

Cathedral

Spires

Meadow

El Capitan

Meadow

Bridalveil

Slaughterhouse

Meadow

Trailhead

Pohono

Merced River

Cathedral Beach

Picnic Area

Wawona Road

El Capitan Trail 

Existing Vegetation and In

Recreational Segme

Retain Building

Water

Meadow

Lower Montane Nee

Lower Montane Bro

Barren

Surfaced Area

Map Area

Segment

4

Segment

3

Segment

2 Segment

1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment

W

SOURCE: NPS, 1997, 2011, 2012
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Common to Alternatives 2–6 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-235

TABLE 9-6: SEGMENT 2 VEGETATION RESTORATION COMMON TO ALTERNATIVES 2-6a

Current Vegetation type Acres Current 

Habitat Type Acres Proposed Future Habitat Type 

Acres Restored 

or Enhanced 

Intermittently to seasonally 

flooded meadow 13 

Meadow 16 

Meadow 18 Semi-permanently to 

permanently flooded meadow 3 

Sparsely vegetated 

undifferentiated 2 Sparsely vegetated 2 

California black oak forest 

alliance 6 

Black oak 

woodland 14 Black oak woodland 14 

California black oak /(bracken 

fern) forest mapping unit 8 

Douglas-fir-(White fir-incense 

cedar-Pondera pine) forest 

mapping unit 

1 

Coniferous forest 58 

A mosaic of 

meadow, black oak, 

and open canopy 

coniferous forest 

58 Ponderosa pine-incense cedar 

forest alliance 18 

Ponderosa pine-incense cedar-

(California black oak-canyon 

live oak) forest superassociation 

39 

Ponderosa pine-incense cedar 

forest alliance 8 

Coniferous forest 25 

Riparian & 

floodplain: 

cottonwood, 

willow, mix of 

upland deciduous & 

coniferous forest 

Ponderosa pine-incense cedar- 25 

(California black oak-canyon 

live oak) forest superassociation 

17 

Urban/developed 4 Development 4 

Riparian: 

cottonwood, 

willow, mix of 

upland deciduous & 

coniferous forest 

36 

Ponderosa pine-incense cedar 

forest alliance 20 

Coniferous forest 32 Ponderosa pine-incense cedar-

(California black oak-canyon 

live oak) forest superassociation 

12 

Total 151 151 151 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 

TABLE 9-7: SEGMENT 2 WETLAND RESTORATION COMMON TO ALTERNATIVES 2-6 

Wetland Type Acres 

Segment 2 

Palustrine Emergent 16.15 

Palustrine Forested 18.85 

Palustrine Scrub Shrub 0.84 

Total amount of wetlands restored 35.84 

SOURCE: NPS 2012c 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-236 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

High visitor use along sensitive riverbanks in Yosemite Valley is causing vegetation trampling and soil 

compaction, resulting in riparian vegetation loss, riverbank erosion, and decreased soil infiltration. In 

some areas, trees are undercut as a result of trampling around the base of the tree, leading to potential 

channel widening. Under Alternatives 2-6, visitors accessing the river would be redirected to resilient 

sandbar points and sandy beaches through signage, campground maps, and brochures. Specific river 

access points would be designated. Parking would be relocated to more suitable areas. Picnic areas 

would be delineated by fencing and river terraces would be revegetated with native riparian species. 

Vulnerable steep slopes and riparian habitats would be fenced off to prevent further bank erosion. 

Some infrastructure (toilets, parking, and picnic tables) within the 10-year floodplain would be 

removed. The proposed redirection of visitor uses to resilient areas away from unstable slopes and 

sensitive locations along riverbanks, and the associated restoration of eroded and denuded areas, 

would generally have a beneficial effect on riparian plant communities. 

These restoration management actions would improve hydrologic function and restore ecological 

integrity of the river corridor in Segment 2 and associated plant communities and wetlands, address 

ongoing and future impacts on park resources and infrastructure, and manage visitor use and 

development along the Merced River corridor. Removing abandoned underground infrastructure, 

restoring informal trails, directing visitor use, and restoring free-flowing conditions along the river 

corridor would be part of a comprehensive strategy to reduce existing adverse impacts on meadow 

and riparian vegetation. Overall, these actions would result in a segmentwide, long-term, moderate, 

beneficial impact on plant communities and wetlands in Segment 2. 

Biological Resource Actions. 

Ahwahnee Meadow: Actions common to Alternatives 2-6 to protect and enhance river values at the 

Ahwahnee Meadow include restoring an impacted portion of the Ahwahnee Meadow to natural 

meadow conditions and removing the tennis courts from black oak woodland. Disjunct portions of 

Ahwahnee Meadow would be reconnected by selectively removing conifers to restore approximately 

5.65 acres of meadow habitat. Enhancing meadow connectivity would reduce meadow fragmentation 

and removal of the tennis courts from black oak woodland would allow for woodland habitat to be 

restored. Natural meadow topography would be restored by removing abandoned irrigation lines and 

fill, filling in ditches, and revegetating with native meadow species. Actions to restore Ahwahnee 

Meadow would have local, long-term, moderate, and beneficial impacts on vegetation and wetlands 

due to an increased amount of meadow and oak woodland habitat, a reduction in habitat 

fragmentation, and enhanced habitat function (restored topography and hydrological connectivity). 

Yosemite Valley Campgrounds: Common to Alternatives 2-6, the NPS would remove all campsites 

within 100 feet of the bed and banks of the Merced River in all Valley campgrounds and restore 

riparian habitat through the removal of asphalt parking spaces, base rock, and fill material. Soils would 

be decompacted and topography would be recontoured to natural conditions. Native riparian plant 

species would be planted to revegetate denuded areas. Riparian habitat protection would be achieved 

through redirecting visitors to more stable and resilient areas, and installation of new fencing (or 

adjusting existing fencing) to protect newly restored riparian zones. Restoration of the 100 feet buffer 

of floodplain and riparian habitat throughout Yosemite Valley would result in segmentwide, longterm, moderate, and beneficial impacts to riparian plant communities. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Common to Alternatives 2–6 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-237

El Capitan Meadow: Common to Alternatives 2-6, the NPS would reroute the climber use trail on the 

north side of the road to an appropriate route (a few meters to the east). Additionally, informal trails 

through meadow and oak woodland habitat would be removed and fencing or natural barriers and 

signs would be installed to keep visitors from trampling sensitive meadow vegetation. Existing culverts 

would be replaced and additional culverts would be installed to improve water flow underneath 

El Capitan Straight on Northside Drive. Encroaching conifer saplings would be removed from 

El Capitan Meadow. Restoration of El Capitan Meadow would result in local, long-term, minor, and 

beneficial impacts on meadow plant communities from reduction in trampling from foot traffic, 

increased hydrological connectivity, and reduced conifer encroachment into meadow habitat. 

Additional actions common to Alternatives 2-6 in Yosemite Valley include: formalizing parking and 

river access from the Pohono Bridge to the Diversion Dam; adding 150 feet of boardwalk to the west of 

the existing boardwalk at Sentinel Meadow; expanding fenced areas to protect wetlands on the north 

end of Stoneman Meadow near Lower Pines Campground; restoring 20 acres of floodplains at the 

western portion of former Lower Pines Campground; removal of infrastructure and restoration of an 

additional 30 acres at the Former Upper and Lower Pines campgrounds; removing roadside parking 

along Sentinel Drive and restoring to natural conditions; relocating parking from Devil’s Elbow to the 

east of the current parking lot and delineating a formal trail to access the sandbar; focusing visitor use 

and river access at Housekeeping Camp to two resilient beach locations on the western edge of 

Housekeeping Camp and across the footbridge; designating formal river access at Cathedral Beach 

Picnic Area and restoring riparian habitat; and filling approximately 2,155 feet of ditches throughout 

Valley meadows that are currently not serving current operational needs. 

These restoration management actions would improve hydrologic function and restore ecological 

integrity of the Merced River corridor and associated plant communities and wetlands, address 

ongoing and future impacts on park resources and infrastructure, and manage visitor use and 

development along the river corridor. These would be part of a comprehensive strategy to reduce 

existing adverse impacts on meadow and riparian vegetation. Thus, these management measures 

would have a segmentwide, long-term, moderate, beneficial impact on plant communities and 

wetlands. 

Hydrologic/Geologic Resource Actions. Specific projects to protect and enhance the river’s 

hydrologic and geologic values that would occur within Segment 2 under Alternatives 2-6 include: 

removing the abandoned gauging station at Pohono Bridge, removing the footings and former river 

gauge base at Happy Isles, and restoring these areas to natural conditions. In addition, constructed log 

jams would be constructed in the channel between Clark’s and Sentinel Bridges to address river 

widening and low channel complexity. These actions would result in enhanced channel free flow, 

increased channel complexity, increased streambank stability, and restored riparian habitat segment. 

Overall these measures would improve the free-flowing condition of the river and restore the 

ecological integrity of Yosemite Valley riparian habitats, resulting in segmentwide, long-term, 

moderate, beneficial impact on riparian plant communities and wetlands.

Cultural Resource Actions. Specific actions to enhance cultural resources in Segment 2 and common 

to Alternatives 2-6 include removing campsite 208 and bear box from the East Valley Campground. 

Additionally, bathroom foot traffic at this campground would be rerouted away from the milling 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-238 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

feature and the feature would be protected by fencing. The removal of campsite 208 and rerouting of 

foot traffic would have long-term, local, negligible, and beneficial impacts on vegetation. 

Scenic Resource Actions. Specific projects to protect and enhance the river’s scenic values that would 

occur within Segment 2 under Alternatives 2-6 include: selectively thinning conifers and other 

vegetation in the vicinities of The Ahwahnee and Meadow, Bridal Veil Falls and West Valley, Cooks 

and Sentinel Meadows, Curry Village, El Capitan, Housekeeping Camp, Yosemite Lodge, and other 

areas of the Valley; restoring grassland and oak habitat in the areas of Bridalveil Straight; repairing 

riverbank erosion at Clark’s Bridge; and addressing informal trails and trampling at the east end of 

El Capitan Meadow. The trees proposed for removal under these actions is summarized in table 9-8. 

The estimated number of trees that would be removed is organized by species and size (NPS 2012b). 

Trees less than 6 inches diameter at breast height (DBH) can be removed in order to maintain a vista 

without additional compliance, and are not included in the estimates. A complete description of these 

scenic vista actions can be found in Appendix H. 

TABLE 9-8: MAXIMUM NUMBER OF TREES REMOVED UNDER ALTERNATIVES 2–6 IN SEGMENT 2

Species 

<12 

inches 

DBH 

<20 

inches 

DBH 

<30 

inches 

DBH 

<40 

inches

DBH 

<50 

inches 

DBH 

<60 

inches 

DBH 

<70 

inches 

DBH Total 

Black Oak 1 1 5 0 0 0 0 7 

Cedar 794 476 234 147 36 2 1 1,690 

Douglas Fir 1 6 1 0 3 0 0 11 

Dogwood 1 0 0 0 0 0 0 1 

White Fir 49 33 34 15 5 1 0 137 

Live Oak 7 3 0 0 0 0 0 10 

Ponderosa 355 277 443 386 94 9 3 1,567 

Total 1,208 796 717 548 138 12 4 3,423 

SOURCE: NPS 2012b

Trees that are removed under Alternatives 2–6 would not substantially fragment existing native 

vegetation communities, reduce species diversity, or substantially reduce the overall size or quality of 

native plant communities in Yosemite Valley. Adherence to proposed mitigation measures MM-GEO-1, 

MM-VEG-2, and MM-VEG-3, as applicable (see Appendix C) would reduce impacts to vegetation 

communities to segmentwide, long-term, minor, and adverse. 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Actions to manage visitor use and facilities within Segment 2 that would occur under actions common 

to Alternatives 2-6 involve changes to campsites, visitor and administrative facilities, employee 

housing, and transportation. Under each action alternative, the NPS would remove or repurpose 

several visitor facilities, including the Curry Village Ice Rink; Happy Isles Snack Stand; Yosemite 

Village Store; Yosemite Lodge Post Office, Yosemite Lodge Pool, and Snack Stand; and Bank Building. 

The NPS would also construct new campsites in upland areas, and remove campsites from the rockfall 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Common to Alternatives 2–6 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-239

hazard zone. Concessioner employee housing within Yosemite Valley would be affected through the 

removal of temporary units at the Yosemite Lodge, Highland Court, Huff House, and Boys Town. 

New housing would be constructed at Huff House (164 beds). Each action alternative includes actions 

to improve pedestrian wayfinding and access. The park would also undertake a number of 

transportation and parking management measures; remediation, redesign, and expansion of existing 

parking areas; and construction of new parking lots in other areas. Vegetation that is removed under 

Alternatives 2–6 would not substantially fragment existing native vegetation communities, reduce 

species diversity, or substantially reduce the overall size or quality of native plant communities in 

Yosemite Valley, as new construction would primarily occur in or adjacent to previously disturbed 

locations or in more resilient, upland habitat. Wetlands would be avoided during construction 

activities common to Alternatives 2-6. Adherence to proposed mitigation measures MM-GEO-1, 

MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as applicable (see Appendix C), and avoidance of 

the removal of vegetation where possible, would reduce short-term impacts to minor and adverse. 

Overall, these actions would result in local, short-term, minor, adverse impacts on plant communities 

in Yosemite Valley. 

Camp 6 & Yosemite Village. Actions in the Camp 6 and Yosemite Village areas that are common to 

Alternatives 2-6 include the relocation of visitor vehicle services and concessioner general office 

functions to other buildings and the removal of the existing garage structure and concessioner general 

office; and transportation actions that formalize parking and public movement in the Camp 6 and 

Village Sport Shop area. Relocation of services and operations to other buildings would have no effect 

upon vegetation and wetlands. Construction activities at Camp 6 and Yosemite Village would result in 

direct, temporary and permanent losses of native vegetation as well as redevelopment of existing 

developed areas. The potential effects of these actions are described in greater under each action 

alternative. 

Outside of previously developed areas, impacts from these actions occur entirely in lower montane 

broadleaf forest and lower montane coniferous forest; these vegetation types are among the most 

dominant communities in Segment 2. Losses to these vegetation communities would occur through 

vegetation clearing, grading, development, or other surface disturbance (e.g., driving over vegetation). 

In addition, potentially affected vegetation at Camp 6 and Yosemite Village are adjacent to already 

developed areas, and therefore currently experience high levels of visitation and human-related 

impacts such as vegetation trampling and soil compaction. Direct impacts to vegetation, including 

trampling or removal of rooted vegetation, would cause a reduction of total numbers of plants and/or 

a reduction or loss of total area, diversity, vigor, structure, or function of vegetative habitat. Direct 

impacts could also include decrease plant vigor or health from reduced water availability or dust 

accumulation on photosynthetic surfaces. 

Vegetation that would be removed at Yosemite Village under actions common to Alternatives 2-6 

would not substantially fragment existing native vegetation communities, reduce species diversity, or 

substantially reduce the overall size or quality of native plant communities in Yosemite Valley, as new 

construction would primarily occur in or adjacent to previously disturbed locations or in more 

resilient upland habitat. Wetlands would be avoided during construction activities. Adherence to 

proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-240 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

applicable (see Appendix C), and avoidance of the removal of vegetation where possible, would reduce 

impacts to local, long-term, minor and adverse. 

As part of these actions, informal parking along Sentinel Drive and several structures in the floodplain 

would also be removed. As discussed under the Impacts of Actions to Protect and Enhance River Values 

section above, these restoration management actions would improve hydrologic function and restore 

ecological integrity of the Merced River corridor in Segment 2 and associated plant communities. This 

action would result in a localized, long-term, minor, beneficial impact to vegetation in Segment 2.

Yosemite Lodge & Camp 4. Actions in the Yosemite Lodge and Camp 4 areas that are common to 

Alternatives 2-6 include the removal of temporary employee housing and the reconstruction of new 

housing. Under all alternatives, the NPS Volunteer Office (former Wellness Center), post office, 

swimming pool, and snack stand would all be removed, and the convenience shop and nature shop 

would be re-purposed. Construction and removal activities at Yosemite Lodge & Camp 4 would result 

in direct temporary and permanent losses of vegetation as well as redevelopment of existing developed 

areas. These losses would occur through vegetation clearing, grading, or other surface disturbance 

(e.g., driving over vegetation) and would occur entirely in lower montane coniferous forest. This is a 

dominant native vegetation community in Segment 2. In addition, vegetation communities at Yosemite 

Lodge & Camp 4 experience high levels of visitation and human-related impacts such as vegetation 

trampling and soil compaction. 

For the same reasons discussed above for the Camp 6 and Yosemite Village area, actions that are 

common to Alternatives 2-6 at Yosemite Lodge and Camp 4 would result in local, short-term, minor, 

adverse impacts to vegetation in Segment 2. 

Segments 3 and 4: Merced Gorge and El Portal 

Impacts of Actions to Protect and Enhance River Values 

To protect and enhance river values within the Merced Gorge and El Portal, the NPS would remove 

informal trails, nonessential roads, fill materials, and abandoned infrastructure throughout Segments 3 

and 4. The Odger’s fuel storage facility would be removed and the area restored. The NPS would also 

develop best management practices for revetment construction and repair throughout the Merced River 

corridor. Valley oaks would be protected in El Portal through mitigation measures related to 

overwatering, tree pruning, and protecting the ground surface within the dripline of oaks (MM-GEO-1 

and MM-VEG-2, as applicable; see Appendix C). Informal trails and a nonessential road would be 

removed from two locations in El Portal. The types of habitat that would be affected by these restoration 

actions in Segment 4, as well as the types of habitat that would be enhanced or restored, are summarized 

in tables 9-9 and 9-10. A total of 12 acres of vegetation would be restored or enhanced in Segment 4, 

including 0.05 acres of wetlands. 

These restoration management actions would improve hydrologic function and restore ecological 

integrity of the Merced River corridor in Segment 4 and associated plant communities and wetlands. 

Overall, these actions would result in a local, long-term, minor, beneficial impact on plant 

communities and wetlands in Segment 4. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Common to Alternatives 2–6 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-241

TABLE 9-9: SEGMENT 4 VEGETATION RESTORATION COMMON TO ALTERNATIVES 2-6a

Current Vegetation type Acres 

Current 

Habitat Type Acres

Proposed Future 

Habitat Type 

Acres Restored 

or Enhanced 

Valley oak woodland alliance 1 Foothill broadleaf 

woodland 1 Valley oak woodland 1 

canyon live oak-(Ponderosa 

pine-incense cedar) forest 

superassociation 

11 Lower montane 

needleleaf 11 Riparian & floodplain 11 

Total 12 12 12 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance 

TABLE 9-10: SEGMENT 4 WETLAND RESTORATION COMMON TO ALTERNATIVES 2-6 

Wetland Type Acres 

Segment 2 

Palustrine Emergent 0.001 

Palustrine Forested 0.05 

Total amount of wetlands restored 0.05 

SOURCE: NPS 2012c 

Biological Resource Actions. Specific projects to protect and enhance the river’s biological values 

that would occur within Segment 4 under Alternatives 2-6 include removing development, asphalt and 

imported fill from the Abbieville and Trailer Village areas. The areas would be recontoured and 

planted with native riparian species and oaks within the 150 foot riparian buffer. The Greenemeyer 

Sandpit contains fill material that precludes natural flooding and regeneration of riparian plant 

communities. Under Alternatives 2-6 the Greenemeyer Sandpit would be restored to natural 

conditions. Fill material would be removed and the topography recontoured. Native riparian 

vegetation would be planted to restore the natural vegetation for the site. Off-street roadside parking 

areas between Foresta Road and the Merced River will be formalized. These restoration management 

actions would improve hydrologic function and restore ecological integrity of the Merced River 

corridor in Segment 4 and associated plant communities and wetlands. Overall, these actions would 

result in a local, long-term, minor, beneficial impact on plant communities and wetlands in Segment 4. 

Scenic Resource Actions. Specific projects to protect and enhance the river’s scenic values that would 

occur within Segment 3 under Alternatives 2-6 include selectively thinning conifers in the area of the 

Cascade Falls viewpoint. Trees proposed to be removed are summarized in table 9-11. The estimated 

number of trees that would be removed is organized by species and size (NPS 2012b). Trees less than 

6 inches diameter at breast height (DBH) can be removed in order to maintain a vista without 

additional compliance, and are not included in the estimates. A complete description of these scenic 

vista actions can be found in Appendix H. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-242 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

TABLE 9-11: MAXIMUM NUMBER OF TREES REMOVED COMMON TO ALTERNATIVES 2–6 IN SEGMENT 3 

Species 

<12 

inches 

DBH 

<20 

inches 

DBH 

<30 

inches 

DBH 

<40 

inches

DBH 

<50 

inches 

DBH 

<60 

inches 

DBH 

<70 

inches 

DBH Total 

Cedar 6 0 0 1 0 0 0 7 

Live Oak 0 1 0 0 0 0 0 1 

Ponderosa 1 1 1 0 0 0 0 3 

Red Fir 3 0 0 0 0 0 0 3 

Total 10 2 1 1 0 0 0 14 

SOURCE: NPS 2012b 

Trees that are removed under Alternatives 2–6 would not substantially fragment existing native 

vegetation communities, reduce species diversity, or substantially reduce the overall size or quality of 

native plant communities in Yosemite Valley. Adherence to proposed mitigation measures MM-GEO-1, 

MM-VEG-2, and MM-VEG-3, as applicable (see Appendix C), would reduce impacts to segmentwide, 

long-term, minor, and adverse. 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Under all the action alternatives, the Park would construct infill housing in El Portal Village Center. All 

housing redevelopment in this area will be outside the 100-year floodplain. All other redevelopment 

will be outside the 150-foot riparian buffer. Vegetation that is removed under Alternatives 2–6 would 

not substantially fragment existing native vegetation communities, reduce species diversity, or 

substantially reduce the overall size or quality of native plant communities at El Portal, as new 

construction would primarily occur in or adjacent to previously disturbed locations or in more 

resilient, upland habitat. Wetlands would be avoided during construction activities. Adherence to 

proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as 

applicable (see Appendix C), and avoidance of the removal of vegetation where possible, would reduce 

short-term impacts to minor and adverse. Overall, these actions would result in local, short-term, 

minor, adverse impacts on plant communities in El Portal. 

Segments 5, 6, 7, and 8: South Fork Merced River 

Impacts of Actions to Protect and Enhance River Values 

Actions to protect and enhance river values that would occur within segments 6 and 7 under 

Alternatives 2–6 include measures to maintain river flows, manage campground waste, and protect 

cultural resources. The park would improve Wawona Campground wastewater and refuse 

management and facilities, remove abandoned infrastructure, and undertake numerous site-specific 

management measures to counteract or minimize ongoing impacts on cultural resources. 

There are abandoned metal pipes in side channels on the South Fork Merced River that dewater the 

terrace. This infrastructure affects the natural hydrologic regime of the river. Under Alternatives 2-6, 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Common to Alternatives 2–6 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-243

abandoned metal pipes would be removed. The South Fork Merced River Wawona picnic area, 

Wawona Store picnic area, and Wawona Swinging Bridge receive high levels of use. There are no formal 

river access points at these sites, and visitors access the river by creating informal trails, causing loss of 

riparian vegetation and riverbank erosion. Under Alternatives 2-6, formal access points to the river 

would be established. This would help reduce impacts on riparian habitat and erosion. The types of 

habitat that would be affected by these restoration actions in Segment 7, as well as the types of habitat 

that would be enhanced or restored, are summarized in table 9-12. A total of three acres of vegetation 

would be restored in Segment 7. 

TABLE 9-12: SEGMENT 7 VEGETATION RESTORATION COMMON TO ALTERNATIVES 2-6a

Current Vegetation type Acres Current 

Habitat Type Acres Proposed Future Habitat Type 

Acres Restored 

or Enhanced 

Ponderosa pine woodland 

alliance 1 

Coniferous forest 3 

Riparian: cottonwood, 

willow, mix of upland 

deciduous & 

coniferous forest 

3 

Ponderosa pine-incense cedar 

forest alliance 2 

Total 3 3 3 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 

These restoration management actions would improve hydrologic function and restore ecological 

integrity of the river corridor in Segment 7 and associated plant communities and wetlands. Overall, 

these actions would result in a segmentwide, long-term, minor, beneficial impact on plant 

communities and wetlands in Segment 7. 

Hydrologic/Geologic Resource Actions. Specific projects to protect and enhance the river’s 

hydrologic values that would occur within Segment 6 under Alternatives 2-6 include implementation 

of the water conservation plan related to the minimum flow analysis for the South Fork Merced River. 

Although the NPS would retain current water collection and distribution system associated with the 

Wawona Impoundment, implementation of this action would reduce water withdrawal rates and 

improve the free-flowing condition of the South Fork Merced River by implementing the water 

conservation plan related to the minimum flow analysis for the South Fork Merced River. This 

management action would improve hydrologic function and restore ecological integrity of the river 

corridor in Segment 6 and associated plant communities and wetlands. Overall, this action would 

result in a segmentwide, long-term, minor, beneficial impact on plant communities and wetlands in 

Segment 6. 

Cultural Resource Actions. Specific projects to protect and enhance the river’s cultural values that 

would occur within Segment 7 under Alternatives 2-6 include removing 7 campsites from Wawona 

Campground that cause potential impacts to sensitive archeological resources. Overall, this action 

would result in a local, long-term, minor, beneficial impact on plant communities and wetlands in 

Segment 6. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-244 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Actions to manage visitor use and facilities within Segments 6 and 7 that would occur under 

Alternatives 2–6 involve construction of and improvements to administrative and visitor-serving 

facilities. Under Alternatives 2–6, the park would improve river access, restroom, picnic, and bus stops 

within Wawona. 

Vegetation that is removed under Alternatives 2–6 would not substantially fragment existing native 

vegetation communities, reduce species diversity, or substantially reduce the overall size or quality of 

native plant communities at Wawona, as new construction would primarily occur in or adjacent to 

previously disturbed locations or in more resilient, upland habitat. Wetlands would be avoided during 

construction activities. Adherence to proposed mitigation measures MM-GEO-1, MM-HYD-1, and 

MM-VEG-1 through MM-VEG-7, as applicable (see Appendix C), and avoidance of the removal of 

vegetation where possible, would reduce short-term impacts to minor and adverse. Overall, these actions 

would result in local, short-term, minor, adverse impacts on plant communities in Wawona. 

The Wawona Maintenance yard currently extends to the riverbank and affects riparian habitat by soil 

compaction, storage of nonnative fill material, and storage of vehicles and other supplies. To reduce 

riparian impacts and restore the area, the NPS would remove staged materials, abandoned utilities, 

vehicles, and the parking lot from the riparian buffer and restore the area to natural conditions. NPS 

would also remove roadside parking between the Wawona Store and Chilnualna Falls Road. These 

restoration management actions would improve hydrologic function and restore ecological integrity of 

the South Fork Merced River corridor in Wawona and associated plant communities and wetlands. 

Overall, these actions would result in a local, long-term, minor, beneficial impact on plant 

communities and wetlands in Wawona. 

Wawona. The only project-level action in the Wawona area that is common to Alternatives 2-6 

involves the redesign of a bus stop to accommodate visitor use. This action would have local, longterm, negligible, adverse impacts on vegetation and wetlands. 

Summary of Impacts Common to Alternatives 2–6 

Alternatives 2–6 would restore approximately 166 acres of vegetation, including 35.89 acres of wetlands. 

Under all action alternatives, the NPS would address some existing adverse impacts on vegetation 

communities (mainly meadows, wetlands, and riparian habitats) and implement restorative management 

actions to improve and restore hydrologic function and restore ecological integrity throughout the 

Merced River corridor, remove and restore informal trails, direct the public onto established trails and 

river access points, restore native plant communities, protect sensitive habitat areas, and minimize risk of 

impacts on new and existing structures associated with flooding. Relocating facilities out of meadow and 

riparian areas; restoring informal trails; controlling river access; eliminating informal parking; and 

delineating formal parking areas, trailheads, and trails would be part of a comprehensive strategy to 

reduce existing adverse impacts on meadow, wetland, and riparian vegetation. Existing natural resource 

management actions, such as removal of nonnative invasive plants, would continue. 

In the long term, these measures would improve hydrologic connectivity of meadows and floodplains 

to the Merced River and South Fork Merced River, enhance habitat complexity in riparian and aquatic 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Common to Alternatives 2–6 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-245

zones, reduce human and pack-related disturbances, and reduce nonnative species and conifer 

intrusion into sensitive habitat. Adverse effects from these actions would be local, short-term, and 

minor or negligible. The long-term effect would be segmentwide, moderate, beneficial impacts on 

vegetation communities within the Merced River corridor. These effects would be most prominent in 

areas of high human use, such as Yosemite Valley and Wawona (Segments 2 and 7). 

Environmental Consequences of Alternative 2: Self-Reliant Visitor Experiences and 

Extensive Floodplain Restoration 

Segment 1: Merced River above Nevada Fall 

Impacts of Actions to Protect and Enhance River Values 

Merced Lake East Meadow near the Merced Lake Ranger Station has high levels of pack stock use, 

which contributes to lower vegetation cover and higher levels of bare ground. Under Alternatives 2, 

grazing would be permanently removed from the Merced Lake East Meadow. The park would require 

administrative pack stock passing through the Merced Lake area to rely on pellet feed that is packed into 

the site instead of allowing pack stock to graze in the meadow. This would help protect meadow 

vegetation from high levels of grazing by reducing the level of vegetation trampling by administrative 

pack stock and reducing the dispersal of manure and roll pits. These actions would have local, minor 

beneficial impacts to vegetation over the long term. 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Several actions related to management of visitor use and facilities would have the potential to affect 

vegetation and wetlands in Segment 1. Visitation within Segment 1 would be reduced through a decrease 

in the Little Yosemite Valley trailhead quota (from 150 to 25), closing of the Merced Lake High Sierra 

Camp, and wilderness campground modifications. Under Alternative 2, there would be a 100% reduction 

in the Merced River corridor’s wilderness lodging units. All 60 units and associated facilities at the Merced 

Lake High Sierra Camp would be removed, resulting in approximately 11 acres of restored meadow and 

subalpine habitat. The park would reduce the total number of designated campsites within the corridor’s 

wilderness. This change would result from the elimination of designated camping at Moraine Dome and 

conversion of the Little Yosemite Valley Backpackers Campground to dispersed camping. Dispersed 

camping at the Merced Lake Backpackers Campground would be increased, but facilities would be 

reduced. Areas either closed or converted to dispersed camping would be restored to natural conditions, 

including restoration of native vegetation communities. 

These management actions would improve hydrologic function and restore ecological integrity of the 

Merced River corridor in Segment 1 and associated plant communities and wetlands. Overall, these 

actions would result in a local, long-term, minor, beneficial impact on plant communities and wetlands 

in Segment 1. 

Merced Lake High Sierra Camp. The actions in the Merced Lake High Sierra Camp area proposed 

under Alternative 2 involve the conversion of the area to designated Wilderness, the closure of the 

Merced Lake High Sierra Camp, and the expansion of dispersed camping at Merced Lake Backpackers 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-246 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Camping Area into the High Sierra Camp footprint. These actions would result in a local, long-term, 

minor, beneficial impact on plant communities and wetlands in Segment 1by reducing impacts on 

vegetation communities related to concentrated human use. 

Segment 1 Impact Summary: Actions to manage visitor use and facilities within Segment 1 would have 

local, long-term, minor, beneficial impacts on plant communities and wetlands along the corridor. 

Segment 2: Yosemite Valley 

Impacts of Actions to Protect and Enhance River Values 

Ecological management actions that would occur within Segment 2 under Alternative 2 include 

measures to restore and protect meadows, riparian habitat, and areas within the 100-year floodplain of 

the Merced River. Projects proposed in Segment 2 to protect and enhance river values involve removal 

of buildings from the Yosemite Lodge area; restoration of 10.9 acres of riparian habitat at the former 

Yosemite Lodge units and cabins; rerouting and re-vegetating the Valley Loop Trail through 

Slaughterhouse Meadow out of wetlands and meadows to an upland area; moving 780 feet of the 

Valley Loop Trail out of Bridalveil Meadow; removing several buildings at Yosemite Lodge out of the 

100-year floodplain and restoring the area. 

Habitat restoration actions in Segment 2 under Alternative 2 are displayed in figures 9-17 through 

9-20. The types of habitat that would be affected by these restoration actions in Segment 2, as well as 

the types of habitat that would be enhanced or restored, are summarized in tables 9-13 and 9-14. A 

total of 271 acres of vegetation would be restored in Segment 2, including 47.92 acres of wetlands (this 

includes restoration actions common to Alternatives 2-6). 

Restoration of these areas would prevent further riverbank erosion, provide hydrologic connectivity for 

meadows and riparian habitats, reduce vegetation trampling, enhance the hydrologic function within the 

2–10 year floodplains, enhance water quality, increase the amount of wildlife habitat, increase 

productivity within riparian and aquatic ecosystems, and reduce human presence and human-related 

impacts. 

These restoration management actions would improve hydrologic function and restore ecological 

integrity of the Merced River corridor in Segment 2 and associated plant communities and wetlands, 

address ongoing and future impacts on park resources and infrastructure, and manage visitor use and 

development along the river corridor. These actions would be part of a comprehensive strategy to reduce 

existing adverse impacts on meadow and riparian vegetation. Overall, these actions would result in a 

segmentwide, long-term, moderate, beneficial impact on plant communities and wetlands in Segment 2. 

Biological Resource Actions. 

Yosemite Valley Campgrounds: Under Alternative 2, specific restoration actions to enhance the river’s 

biological values in Segment 2 include removing all campsites within 100 feet of the bed and banks of the 

Merced River and restoring 25.1 acres of floodplain/riparian habitat, and removing all informal trails and 

reducing roadside parking at El Capitan Meadow. Restoration of riparian habitat throughout Yosemite 

Valley would result in segmentwide, long-term, moderate, and beneficial impacts to vegetation. 
N or th Pines

C ampgr o und

R

Stoneman

Bridge

L ower Pines

C ampground

Stoneman

M eadow

C lark's

Bridge

B ackpackers

C ampground

Ahwahnee

Bridge

Sugar Pine

Bridge

Ahwahnee H otel

H istoric L andmark

H appy

Isles Bridge

H appy Isles

Nature C enter

se

U pper Pines

C ampgr o und

H ousekeeping

C amp

C amp C urry V illage

Stock

Bridge

H ousekeeping

C amp Bridge

H appy

Isles Fen

Sou hs t di e Dr vi e

L eC onte M emorial L odge

H istoric L andmark

M erced R I ver

N orthside D rive

Stables A rea

0 0.125 0.25

Miles

Existing Vegetation and Infrastructure

Surfaced AreaBarrenLower Montane BroadleafLower Montane NeedleleafMeadowWaterRetain BuildingCampgroundRecreational Segment Corridor Classification

Habitat Restoration Actions

Bridge Removal; Infrastructure RemovalDump Station RemovalRiver AccessRemove BuildingRemove RoadBlack Oak RestorationMeadow RestorationRiparian RestorationRiparian and Floodplain Restoration

BoardwalkRemove informal trailBrush layerFill ditchFill removalNew fencingRemove pipeKeep riprap and plantRemove riprap and bioengineerRemove riprap and revegetateRoad removal; Trail removalRevegetate

Merced River Comprehensive Management Plan and EIS . 210436

Figure 9-17

Curry Village Area: Alternative 2 Habitat Restoration Actions

and Select Facilities Actions

SOURCE: NPS, 1997, 2011, 2012

Map Area

Segment

4

Segment

3

Segment

2 Segment 1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment

Curry Village Impact Area
Bridge

Sentinel

Merced R iver

R oyal Arch C reek

BridgeStoneman

C ampground

L ower Pines

M eadow

Stoneman

L ost A rrow Drive

L ost A rrow D rive

Ahwahnee

Bridge

Arch C ascadeR oyal

Village Drive

H ousekeeping

C amp

Superintendent's

Bridge

C amp BridgeH ousekeeping

walk

N orths di e D rive

N

orthside

Drive

R angers' C lub

H istoric L andmark

C hapelYosemite Valley

T he A hwahnee H otel

H istoric L andmark

Yo sem ite V i llage

N orthside D rive

Southside D rive

Oak L ane

Sentinel C rossover

Tecoya R oad

Tenaya W

ay

C amp 6 R oad

C edar L ane

a C st el il C Cff r uo t

Bou dl er L na e

Ahwahnee R oad

C ook's

M eadow

M eadow

Ahwahnee

M eadow

Sentinel

Existing Vegetation and Infrastructure

Recreational Segment Corridor ClassificationRetain BuildingCampgroundWaterMeadowLower Montane NeedleleafLower Montane BroadleafBarrenSurfaced Area

Habitat Restoration Actions

Road mitigation

Riparian and Floodplain RestorationRiparian RestorationMeadow RestorationBlack Oak RestorationRemove RoadRemove BuildingRiver AccessBridge Removal; Infrastructure Removal

RevegetateRoad removal; Trail removalRemove riprap and revegetateRemove riprap and bioengineerKeep riprap and plantNo Action for riprapNew fencingFill removalFill ditchBrush layerRemove informal trail

Merced River Comprehensive Management Plan and EIS . 210436

Figure 9-18

Yosemite Village Area: Alternative 2 Habitat Restoration Actions

and Select Facilities Actions

SOURCE: NPS, 1997, 2011, 2012

0 0.125 0.25

Miles

Map Area

Segment

4

Segment

3

Segment

2 Segment

1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment

Camp 6 & Yosemite Village Impact Area
Camp 4

Historic Site

Yosemite Lodge

Sentinel

Beach

Leidig

Meadow

Swinging

Bridge

Yosemite Lodge Road

Nor ht s di e Dr vi e

Sou 

Wahhoga

Merced RIver

Sentinel Beach

Picnic Area

Swinging Bridge

Picnic Area

Lower Yosemite

Fall Picnic Area Yosemite Lodge & Camp 4 Impact Area

Existing Vegetation and Infrastructure

Surfaced Area

Barren

Lower Montane Broadleaf

Lower Montane Needleleaf

Meadow

Water

Retain Building

Campground

Recreational Segment Corridor Classification

Habitat Restoration Actions

River Access

Remove Building

Black Oak Restoration

Meadow Restoration

Riparian Restoration

Riparian and Floodplain Restoration

Road mitigation

Boardwalk

Remove informal trail

New fencing

No Action for riprap

Keep riprap and plant

Remove riprap and bioengineer

Remove riprap and revegetate

SOURCE: NPS, 1997, 2011, 2012
Cathedral Beac

Bridge

El Capitan

Pohono

Bridge

UV140

|ÿ41

Northside Drive

El

Capitan

Leaning

Tower

Cathedral

Rocks

Cathedral

Spires

Meadow

El Capitan

Meadow

Bridalveil

Slaughterhouse

Meadow

Trailhead

Pohono

) ) )

Merced River

Cathedral Beach

Picnic Area

Wawona Road

El Capitan Trail 

Yosemite Lodge & Camp 4 

Existing Vegetation and Infrastr

Recreational Segment Cor

Campground

Retain Building

Water

Meadow

Lower Montane Needlelea

Lower Montane Broadleaf

Barren

Surfaced Area

Map Area

Segment

4

Segment

3

Segment

2 Segment

1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment

SOURCE: NPS, 1997, 2011, 2012
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 2 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-251

TABLE 9-13: SEGMENT 2 VEGETATION RESTORATION UNDER ALTERNATIVE 2a

Current Vegetation Acres 

Current 

Habitat Type Acres

Proposed Future 

Habitat Type 

Acres Restored 

or Enhanced 

Urban/Developed 0.4 Barren 0 

Meadow 20 

Intermittently to seasonally 

flooded meadow 15 

Semi-permanently to Meadow 18 

permanently flooded 

meadow 

3 

Sparsely vegetated 

undifferentiated 2 Sparsely vegetated 2 

Black cottonwood 

temporarily flooded forest 

alliance 

1 

Lower montane 

broadleaf 16 Lower montane broadleaf California black oak forest 16 

alliance 7 

California black oak /(bracken 

fern) forest mapping unit 8 

Douglas-fir-(White fir-incense 

cedar-Pondera pine) forest 

mapping unit 

1 

Lower montane 

needleleaf 75 

A mosaic of meadow, 

black oak, and open 

canopy coniferous 

forest 

75 

Ponderosa pine woodland 

alliance 0.3 

Ponderosa pine-incense cedar 

forest alliance 27 

Ponderosa pine-incense 

cedar-(California black oakcanyon live oak) forest 

superassociation 

47 

Urban/Developed 9 Barren 9 

Riparian & floodplain 152 

Black cottonwood 

temporarily flooded forest 

alliance 

1 Lower montane 

broadleaf 1 

Ponderosa pine-incense cedar 

forest alliance 73 

Lower montane 

needleleaf 142 

Ponderosa pine-incense 

cedar-(California black oakcanyon live oak) forest 

superassociation 

68 

Douglas-fir-(White fir-incense 

cedar-Pondera pine) forest 

mapping unit 

1 

Ponderosa pine-incense 

cedar-(California black oakcanyon live oak) forest 

superassociation 

8 Lower montane 

needleleaf 8 Riparian 8 

Total 271 271 271 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-252 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

TABLE 9-14: SEGMENT 2 WETLAND RESTORATION UNDER ALTERNATIVE 2 

Wetland Type Acres 

Segment 2 

Palustrine Emergent 20.07 

Palustrine Forested 26.23 

Palustrine Scrub Shrub 1.62 

Total amount of wetlands restored 47.92 

SOURCE: NPS 2012c 

El Capitan Meadow: In addition to actions common to Alternatives 2-6, the NPS would remove all 

informal trails and reduce roadside parking through alternative striping and consolidate parking to the 

west end of the meadow to reduce impacts to El Capitan Meadow. Restoration of El Capitan Meadow 

and elimination of roadside parking adjacent to the meadow would result in local, long-term, minor, 

and beneficial impacts on vegetation from reduction in trampling from foot traffic and impacts to 

meadow habitat associated with roadside parking. 

Ahwahnee Meadow: Specific actions under Alternative 2 in Segment 2 to enhance the river’s 

biological values at the Ahwahnee Meadow include: rerouting or removing trails which traverse 

wetlands in the Ahwahnee meadow and consolidating trail use with the Housekeeping Footbridge trail 

where possible, removing 900 feet of Northside Drive and relocating the bike path to the south of 

Ahwahnee Meadow, and restoring meadow contours and native vegetation. Meadow restoration, trail 

rerouting and removal, and removal of a portion of Northside Drive would result in local, long-term, 

moderate, and beneficial impacts on vegetation at the Ahwahnee Meadow as wetland fragmentation 

and vegetation trampling is reduced, and wetland connectivity to the river is enhanced. 

Stoneman Meadow: Under Alternative 2, the park would restore Stoneman Meadow by removing 

1,335 feet of Southside Drive and re-aligning the road through Boys Town area. The Orchard Parking 

Lot would be redesigned and engineering solutions would be applied to promote water flow and 

improve meadow health to increase drainage from the cliff walls to Stoneman Meadow. The meadow 

boardwalk would be extended through wet areas to Curry Village (up to 275 feet). Restoration of 

Stoneman Meadow and protection of sensitive wetland habitat would result in local, long-term, minor 

to moderate, and beneficial impacts on meadow vegetation. 

Former Upper and Lower Rivers Campgrounds: Specific actions to enhance biological values of the 

Merced River at the Former Upper and Lower Rivers Campgrounds in Alternative 2 include restoring 

30 acres of the 10-year floodplain. Under Alternative 2, the park would remove the remaining asphalt, 

decompact soils of former roads and campsites, and re-establish seasonal channels and natural 

topography that have been filled. Additionally, the park would remove the Lower River amphitheater 

structure and fill. Following habitat restoration, temporary fencing would be installed to protect the 

restoration areas and to allow for recovery. Restoration of the Former Upper and Lower Rivers 

Campgrounds would result in local, long-term, moderate, and beneficial impacts on riparian vegetation. 

These restoration management actions would improve hydrologic function and restore ecological 

integrity of the Merced River corridor in Segment 2 and associated plant communities and wetlands, 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 2 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-253

address ongoing and future impacts on park resources and infrastructure, and manage visitor use and 

development along the river corridor. These actions would be part of a comprehensive strategy to 

reduce existing adverse impacts on meadow and riparian vegetation. Overall, these actions would 

result in a segmentwide, long-term, moderate, beneficial impact on plant communities and wetlands in 

Segment 2. 

Hydrologic/Geologic Resource Actions. Specific projects to protect and enhance the river’s 

hydrologic and geologic values that would occur within Segment 2 under Alternative 2 include: 

relocating unimproved Camp 6 parking and rerouting a portion of Northside Drive; removing the 

Stoneman, Ahwahnee and Sugar Pine Bridges; and restoring these areas to natural conditions. These 

actions would result in enhanced channel free flow, increased channel complexity, increased 

streambank stability, and restored riparian habitat segmentwide. Overall these measures would 

improve the free-flowing condition of the river and restore the ecological integrity of Yosemite Valley 

riparian habitats, resulting in segmentwide, long-term, moderate beneficial impacts on plant 

communities and wetlands in Segment 2. 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Alternative 2 would significantly reduce the maximum daily visitation to Yosemite Valley from current 

levels to facilitate maximum resource restoration and reduce crowding and congestion within Segment 2. 

Actions to manage visitor use and facilities under Alternative 2, specifically those concerning vehicle 

access and number of overnight accommodations, would result in a 33% decrease in daily Yosemite 

Valley visitation, from approximately 20,900 to 13,900. Day use visitation would decrease by 36%, while 

overnight visitation would decrease by 26%. Under Alternative 2, there would also be a reduction in 

Valley lodging units. Changes in lodging would include the removal of units from Housekeeping Camp, 

conversion of the Yosemite Lodge to a day use facility, and an increase in units at Curry Village. The park 

would reduce the total number of campsites within the Valley. This change stems largely from campsite 

removals at Upper Pines, Lower Pines, and North Pines campgrounds, and additions at Yosemite Lodge. 

Actions to significantly limit day use activities, overnight capacities, and day parking would effectively 

reduce the built environment and human presence within the Valley. Restoration of habitat following 

the removal of facilities and parking lots would increase the extent and contiguity of plant 

communities and wetlands; limiting day use activities and roadside parking would reduce impacts on 

sensitive habitats, such as riparian woodland and wet meadows; and reducing overnight capacities 

would reduce human pressures on vegetation and wetlands in general. 

Relocation of facilities to other locations within the corridor could have long-term, negligible to 

moderate, adverse effects on vegetation, depending on site-specific conditions and project design. 

Local, minor to moderate, short-term, adverse effects could occur from construction and demolition 

of facilities along the Merced River. Vegetation that is removed under Alternative 2 would not 

substantially fragment existing native vegetation communities, reduce species diversity, or 

substantially reduce the overall size or quality of native plant communities in Yosemite Valley, as new 

construction would primarily occur in or adjacent to previously disturbed locations or in more 

resilient, upland habitat. Wetlands would be avoided during construction activities. Adherence to 

proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-254 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

applicable (see Appendix C), and avoidance of the removal of vegetation where possible, would reduce 

short-term impacts to local, minor and adverse. 

The overall reduction in infrastructure, lodging units, and campsites and subsequent restoration under 

Alternative 2 would benefit vegetation communities in Yosemite Valley in the long-term. These 

restoration management actions would improve hydrologic function and restore ecological integrity of 

the Merced River corridor in Segment 2 and associated plant communities and wetlands, address 

ongoing and future impacts on park resources and infrastructure, and manage visitor use and 

development along the river corridor. These actions would be part of a comprehensive strategy to reduce 

existing adverse impacts on meadow and riparian vegetation. Overall, these actions would result in a 

segmentwide, long-term, moderate, beneficial impact on plant communities and wetlands in Segment 2. 

Curry Village & Campgrounds. Actions under Alternative 2 in Segment 2 related to managing visitor 

use and facilities at Curry Village include the construction of 78 hard-sided units at Boys Town. The 

units would be constructed within previously developed areas as well as within vegetation 

communities adjacent to the existing Curry Village site. 

Construction activities at Curry Village would result in direct, temporary and permanent losses of 

native vegetation and wetlands (see table 9-15) as well as redevelopment of existing developed areas. 

Outside of previously developed areas, impacts to vegetation would occur in lower montane 

coniferous forest and, to a much lesser extent, meadow. Losses would occur through vegetation 

clearing, grading, site development or other surface disturbance (e.g., driving over vegetation). As 

shown in table 9-15 below, only a small percentage of these vegetation communities would be affected 

by the facility actions at Curry Village. Impacts to meadow habitat would occur in a small meadow area 

currently disconnected from the larger Stoneman Meadow to the north by Happy Isle Loop Road. In 

addition, vegetation communities at Curry Village are adjacent to already developed areas, and 

therefore currently experience high levels of visitation and human-related impacts such as vegetation 

trampling and soil compaction. Therefore, losses of vegetation communities, while long-term, would 

be local, adverse and minor. 

TABLE 9-15: VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR USE AND 

FACILITIES AT CURRY VILLAGE & CAMPGROUNDS – ALTERNATIVE 2 

Vegetation/Wetland Type Acres 

Percent of Vegetation/Wetland 

Type Affected in Segmenta

Segment 2 

Meadow 0.03 <0.1% 

Lower Montane Coniferous 6.35 <0.1% 

Redevelopmentb 1.97 N/A 

Wetland (Palustrine Emergent) 0.04 <0.1% 

Wetland (Riverine Intermittent) 0.02 <0.1% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 2 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-255

Direct impacts to vegetation, including trampling or removal of rooted vegetation, would cause a 

reduction of the total numbers of plants and/or a reduction or loss of total area, diversity, vigor, 

structure, or function of vegetative habitat. Direct impacts could also include decrease plant vigor or 

health from reduced water availability or dust accumulation on photosynthetic surfaces. 

Vegetation that would be removed at Curry Village under Alternative 2 would not substantially 

fragment existing native vegetation communities, reduce species diversity, or substantially reduce the 

overall size or quality of native plant communities in Yosemite Valley, as new construction would 

primarily occur in or adjacent to previously disturbed locations or in more resilient upland habitat. 

Wetlands would be avoided during construction activities. Adherence to proposed mitigation 

measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as applicable (see 

Appendix C), and avoidance of the removal of vegetation where possible, would reduce impacts to 

local, long-term, minor and adverse. 

Construction activities at Curry Village would result in direct, permanent losses of federally protected 

wetlands. Impacts to wetlands would occur in palustrine emergent wetlands associated with Stoneman 

Meadow and intermittent channels flowing through the area. Approximately 0.06 acres of potentially 

jurisdictional wetland features would be directly and permanently impacted by the proposed actions 

under Alternative 2. Losses to these wetlands would occur through site clearing, filling, grading, and 

subsequent development. Construction activities may also generate indirect impacts to wetlands 

including potential modifications to flow, circulation, hydroperiod, or other aspects of the hydrologic 

regime, and increases in sedimentation due to ground disturbance associated with construction. 

However, post-construction, temporarily impacted areas would be restored. Wetlands that cannot be 

avoided and would be permanently filled must be compensated to result in “no net loss” of wetlands. 

Adherence to proposed mitigation measures MM-HYD-1, MM-VEG-1, and MM-VEG-4 through 

MM-VEG-7, as applicable (see Appendix C), and avoidance of wetlands during construction where 

possible, would reduce impacts to wetlands to local, long-term, minor and adverse. 

Camp 6 and Yosemite Village. Actions under Alternative 2 in Segment 2 related to managing visitor 

use and facilities at Camp 6 and Yosemite Village include measures to formalize and relocate parking 

facilities and Northside Drive outside the 10-year floodplain. The Camp 6/Village Center Parking Area 

would be formalized to include 550 designated parking spaces by redeveloping part of the current 

administrative footprint. In addition, 100 parking spaces would be added at Yosemite Village. 

Northside Drive would be rerouted south of the parking areas and out of the dynamic 10-year 

floodplain. Fill material would be removed from the floodplain and the area would be restored to 

meadow and floodplain ecosystems. Expanded parking areas and new road construction activities at 

Yosemite Village would result in direct, temporary and permanent losses of native vegetation and 

wetlands (see table 9-16) as well as redevelopment of existing disturbed areas. 

As noted in table 9-16, over half of the area affected by the above actions would occur at sites that are 

already developed. Outside of previously developed areas, impacts to vegetation would occur entirely 

in lower montane broadleaf forest and lower montane coniferous forest; these types are among the 

most dominant native vegetation communities in Segment 2. Losses to these communities would occur 

through vegetation clearing, grading, site development or other surface disturbance (e.g., driving over 

vegetation). As shown in table 9-16, only a small percentage of these vegetation communities would be 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-256 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

TABLE 9-16: VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR USE AND 

FACILITIES AT CAMP 6 & YOSEMITE VILLAGE – ALTERNATIVE 2 

Vegetation/Wetland Type Acres 

Percent of 

Vegetation/Wetland Type 

Affected in Segmenta

Segment 2 

Lower Montane Coniferous 9.03 0.1% 

Lower Montane Broadleaf 1.37 <0.1% 

Redevelopmentb 11.55 N/A 

Wetland (Palustrine Emergent) 0.77 0.3% 

Wetland (Palustrine Forested) 1.52 1.3% 

Wetland (Riverine Intermittent) 0.35 0.2% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 

impacted by the actions at Camp 6 and Yosemite Village. In addition, potentially affected vegetation is 

adjacent to already developed areas, and therefore experience high levels of visitation and humanrelated impacts such as vegetation trampling and soil compaction. Therefore, losses of vegetation 

communities, while long-term, would be local, adverse and minor. 

Vegetation that would be removed at Camp 6 and Yosemite Village under Alternative 2 would not 

substantially fragment existing native vegetation communities, reduce species diversity, or 

substantially reduce the overall size or quality of native plant communities in Yosemite Valley, as new 

construction would primarily occur in or adjacent to previously disturbed locations or in more 

resilient upland habitat. Adherence to proposed mitigation measures MM-GEO-1, MM-HYD-1, and 

MM-VEG-1 through MM-VEG-7, as applicable (see Appendix C), and avoidance of the removal of 

vegetation where possible, would reduce impacts to local, long-term, minor and adverse. The 

rerouting of Northside Drive at Camp 6 outside the 10-year floodplain would result in the restoration 

of floodplain and meadow habitats. As discussed under the Impacts of Actions to Protect and Enhance 

River Values section above, this restoration management action would improve hydrologic function 

and restore ecological integrity of the Merced River corridor in Segment 2 and associated plant 

communities. Overall, this action would result in a localized, long-term, moderate, beneficial impact on 

plant communities and wetlands in Segment 2. 

Parking areas and new road construction activities at Camp 6 and Yosemite Village would result in 

direct, permanent losses of federally protected wetlands. Impacts to wetlands would occur in palustrine 

emergent wetlands located adjacent to the Northside Drive and Sentinel Crossover intersection, 

palustrine forested wetlands associated with the Merced River, and intermittent channels flowing 

through the area. Approximately 2.61 acres of potentially jurisdictional wetland features would be 

directly and permanently impacted by the proposed actions under Alternative 2. Losses to these 

wetlands would occur through site clearing, filling, grading, and subsequent development. Construction 

activities may also generate indirect impacts to wetlands including potential modifications to flow, 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 2 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-257

circulation, hydroperiod, or other aspects of the hydrologic regime, and increases in sedimentation due 

to ground disturbance associated with construction. However, post-construction, temporarily impacted 

areas would be restored. Wetlands that cannot be avoided and would be permanently filled must be 

compensated to result in “no net loss” of wetlands. Adherence to proposed mitigation measures MMHYD-1, MM-VEG-1, and MM-VEG-4 through MM-VEG-7, as applicable (see Appendix C), and 

avoidance of wetlands during construction where possible, would reduce impacts to wetlands to local, 

long-term, minor and adverse. 

Yosemite Lodge and Camp 4. Actions under Alternative 2 in Segment 2 related to managing visitor 

use and facilities at Yosemite Lodge and Camp 4 include the conversion of Yosemite Lodge to a dayuse facility and the addition of 250 parking spaces; redevelopment west of Yosemite Lodge to provide 

an additional 150 day use parking spaces and area for 15 tour buses; the removal of old and temporary 

housing at Highland Court and the Thousands Cabins; the conversion of Highland Court to a walk-in 

campground; and the relocation of the pedestrian crossing at Northside Drive and Yosemite Lodge 

Drive to alleviate pedestrian/vehicle conflicts. 

Like other proposed facility projects, construction activities at Yosemite Lodge would result in direct 

temporary and permanent losses of native vegetation and wetlands as well as the redevelopment of 

existing disturbed areas (table 9-17). Impacts to vegetation would occur entirely in lower montane 

coniferous forest, the dominant natural vegetation community in Segment 2. Losses would occur 

through vegetation clearing, grading, site development or other surface disturbance (e.g., driving over 

vegetation). As shown in table 9-17, only a small percentage of this vegetation community would be 

impacted. In addition, potentially affected vegetation communities are adjacent to already developed 

areas, and therefore experience high levels of visitation and human-related impacts such as vegetation 

trampling and soil compaction. Therefore, losses of vegetation communities, while long-term, would 

be local, adverse and minor. 

TABLE 9-17: VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR USE AND 

FACILITIES AT YOSEMITE LODGE AND CAMP 4 – ALTERNATIVE 2 

Vegetation/Wetland Type Acres 

Percent of 

Vegetation/Wetland Type 

Affected in Segmenta

Segment 2 

Meadow 0.12 <0.1% 

Lower Montane Coniferous 14.90 0.2% 

Lower Montane Broadleaf 0.57 <0.1% 

Redevelopmentb 3.69 N/A 

Wetland (Palustrine Emergent) 0.12 <0.1% 

Wetland (Riverine Intermittent) 0.03 <0.1% 

Wetland (Riverine Perennial) 0.02 <0.1% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-258 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Like other development actions proposed under this alternative, vegetation that would be removed at 

Yosemite Lodge under Alternative 2 would not substantially fragment existing native vegetation 

communities, reduce species diversity, or substantially reduce the overall size or quality of native plant 

communities in Yosemite Valley, as new construction would primarily occur in or adjacent to previously 

disturbed locations or in more resilient upland habitat. Wetlands would be avoided during construction 

activities. Adherence to proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 

through MM-VEG-7, as applicable (see Appendix C), and avoidance of the removal of vegetation 

where possible, would reduce impacts to local, long-term, minor and adverse. 

Construction activities at Yosemite Lodge and Camp 4 would result in direct, permanent losses of 

federally protected wetlands. Impacts to wetlands would occur to palustrine emergent wetlands along 

the Merced River and in intermittent channels flowing through the area. Approximately 0.17 acre of 

potentially jurisdictional wetland features would be directly and permanently impacted by the 

proposed actions at Yosemite Lodge and Camp 4 under Alternative 2. Losses to these wetlands would 

occur through site clearing, filling, grading, and subsequent development. Construction activities may 

also generate indirect impacts to wetlands including potential modifications to flow, circulation, 

hydroperiod, or other aspects of the hydrologic regime, and increases in sedimentation due to ground 

disturbance associated with construction. However, post-construction, temporarily impacted areas 

would be restored. Wetlands that cannot be avoided and would be permanently filled must be 

compensated to result in “no net loss” of wetlands. Adherence to proposed mitigation measures MMHYD-1, MM-VEG-1, and MM-VEG-4 through MM-VEG-7, as applicable (see Appendix C), and 

avoidance of wetlands during construction where possible, would reduce impacts to wetlands to local, 

long-term, minor and adverse. 

As summarized in table 9-18, actions to manage visitor use and facilities would result in the loss of 

approximately 32.37 acres of vegetation primarily located near previously developed areas, resulting in 

a long-term, local, minor, adverse impacts to the affected plant communities. Actions to manage visitor 

use and facilities would result in the loss of 2.87 acres of potentially jurisdictional wetlands. 

TABLE 9-18: SUMMARY OF VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR USE 

AND FACILITIES IN SEGMENT 2 – ALTERNATIVE 2 

Vegetation/Wetland Type Acres 

Percent of 

Vegetation/Wetland Type 

Affected in Segmenta

Segment 2 

Meadow 0.15 <0.1% 

Lower Montane Coniferous 30.28 0.4% 

Lower Montane Broadleaf 1.94 <0.1% 

Redevelopmentb 17.21 N/A 

Wetland 2.87 0.5% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 2 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-259

Segment 2 Impact Summary: Actions to protect and enhance river values within Segment 2 under 

Alternative 2 would result in the restoration of approximately 271 acres of vegetation and 47.92 acres 

of wetland, resulting in long-term, segmentwide, major, beneficial impacts on vegetation and wetlands. 

Actions to manage visitor use and facilities would result in the loss of approximately 32.37 acres of 

vegetation primarily located near previously developed areas, resulting in a long-term, local, minor to 

moderate, adverse impacts to the affected plant communities. Actions to manage visitor use and 

facilities would result in the loss of 2.87 acres of potentially jurisdictional wetlands. 

Segments 3 and 4: Merced Gorge and El Portal 

Impacts of Actions to Protect and Enhance River Values 

Currently, vehicles park under the dripline of the 38 valley oak trees. This practice compacts soil under 

the trees, affecting root health, water uptake, and soil aeration. Additionally, existing development and 

trampling in the vicinity limits the area where oak seedlings can be recruited. Under Alternative 2, 

valley oaks in El Portal would be enhanced by creating an oak recruitment area of 2.25 acres in 

Old El Portal in the vicinity of the current bulk fuel storage area, including the adjacent parking lots. 

Parking and new building construction within the oak recruitment area would be prohibited. 

Nonnative fill would be removed and soils decompacted. Appropriate native understory plant species 

would be planted. The fuel storage area would be relocated outside of the river corridor. Overall, these 

actions would result in local, long-term, moderate, beneficial impacts on valley oaks in El Portal. 

The types of habitat that would be affected by these restoration actions in Segment 4, as well as the 

types of habitat that would be enhanced or restored, are summarized in tables 9-19 and 9-20. A total 

of 13 acres of vegetation would be enhanced or restored in Segment 4, including 0.05 acre of wetlands 

(this includes restoration actions common to Alternatives 2-6). 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Under Alternative 2, user capacity is largely affected by the increase in employee housing at El Portal in 

this segment. In Alternative 2, NPS employee housing would be added to Abbieville, El Portal Village 

Center, and Rancheria Flat; employee parking would be added at Rancheria, El Portal, and Abbieville. 

While all new units would be constructed outside of the 100-year floodplain, they would fall within the 

Merced River corridor. This increase in capacity in El Portal is a function of the decrease in employee 

housing capacity in Yosemite Valley (Segment 2). Administrative campsites from the Yellow Pine 

Campground would also be relocated to this area. The addition of employee housing and park 

facilities development would increase the total built environment within Segment 4. 

Relocation of facilities to other locations within the corridor could have long-term, negligible to 

moderate, adverse effects on vegetation, depending on site-specific conditions and project design. 

Local, minor to moderate, short-term, adverse effects could occur from construction and demolition 

of facilities along the Merced River. Vegetation that is removed under Alternative 2 would not 

substantially fragment existing native vegetation communities, reduce species diversity, or 

substantially reduce the overall size or quality of native plant communities at El Portal, as new 

construction would primarily occur in or adjacent to previously disturbed locations or in more 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-260 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

TABLE 9-19: SEGMENT 4 VEGETATION RESTORATION UNDER ALTERNATIVE 2a

Current Vegetation Acres 

Current 

Habitat Type Acres

Proposed Future 

Habitat Type 

Acres Restored 

or Enhanced 

Valley oak woodland alliance 2 Foothill broadleaf 

woodland 2 Valley oak woodland 2 

Sparsely vegetated riverine 

flat 2 Sparsely vegetated 2 

Riparian & floodplain 11 canyon live oak-(Ponderosa 

pine-incense cedar) forest 

superassociation 

9 Lower montane 

broadleaf 9 

Total 13 13 13 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 

TABLE 9-20: SEGMENT 4 WETLAND RESTORATION UNDER ALTERNATIVE 2 

Wetland Type Acres 

Segment 4 

Palustrine Emergent 0.001 

Palustrine Forested 0.05 

Total amount of wetlands restored 0.05 

SOURCE: NPS 2012c 

resilient, upland habitat. Wetlands would be avoided during construction activities. Adherence to 

proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as 

applicable (see Appendix C), and avoidance of the removal of vegetation where possible, would reduce 

short-term impacts to minor and adverse. Overall, these actions would result in local, short-term, 

minor, adverse impacts on plant communities in El Portal. 

Segments 3 and 4 Impact Summary: Actions to protect and enhance river values within Segments 3 

and 4 under Alternative 2 would result in the restoration of 13 acres of vegetation and 0.05 acres of 

wetland, resulting in long-term, local, moderate, beneficial impacts on vegetation and wetlands. 

Actions to manage visitor use and facilities would result in short-term, local, minor, adverse impacts to 

vegetation and wetlands. 

Segments 5, 6, 7, and 8: South Fork Merced River 

Impacts of Actions to Protect and Enhance River Values 

The Wawona Golf Course is located in a former meadow, altering vegetation patterns, compacting 

soils, and interrupting meadow hydrology. Under Alternative 2, the Wawona Golf Course would be 

decommissioned and the area restored to native meadow habitat through recontouring topography 

and re-vegetation. These actions would collectively improve meadow and wetland habitat integrity, 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 2 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-261

increase the extent of Wawona Meadow, and enhance contiguity of the meadow habitat with the rest 

of Wawona Meadow. These actions would also enhance hydrological connectivity between meadow, 

riparian, and floodplain habitats. Overall, these actions would result in a local, long-term, major, 

beneficial impact on plant communities and wetlands in Wawona. 

The types of habitat that would be affected by these restoration actions in Segment 7, as well as the 

types of habitat that would be enhanced or restored, are summarized in table 9-21. A total of 52 acres 

of vegetation would be restored in Segment 7 (this includes restoration actions common to 

Alternatives 2-6). 

TABLE 9-21: SEGMENT 7 VEGETATION RESTORATION UNDER ALTERNATIVE 2a

Current Vegetation Acres 

Current 

Habitat Type Acres

Proposed Future 

Habitat Type 

Acres Restored 

or Enhanced 

Urban/Developed 40 Barren 40 Meadow 40 

Ponderosa pine woodland 

alliance 3 Lower montane needleleaf 3 

Riparian & floodplain: 

cottonwood, willow, mix 

of upland deciduous & 

coniferous forest 

3 

Ponderosa pine-incense 

cedar forest alliance 8 Lower montane needleleaf 8 Riparian: cottonwood, 

willow, mix of upland 

deciduous & coniferous 

forest 

9 

Ponderosa pine woodland 

alliance 1 Lower montane needleleaf 1 

Total 52 52 52 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 

Biological Resource Actions. Specific projects to protect and enhance the river’s biological values 

that would occur within Segment 7 under Alternative 2 include the relocation of stock use campsites 

from sensitive resource areas to Wawona Stables. Overall, this action would result in a local, long-term, 

minor, beneficial impact on plant communities and wetlands in Wawona.

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Under Alternative 2, the operations of the Wawona Stables would be eliminated and two stock 

campsites would be relocated to this area from the current Wawona Stock Camp. The Wawona tennis 

courts would be removed. Campsites in Wawona Campground are located in proximity to the river, 

resulting in trampling of riparian vegetation and riverbank erosion. Under Alternative 2, campsites 

within the 100-year floodplain would be removed and the area would be restored. Soils would be 

decompacted and the area would be replanted with riparian vegetation. This would reduce visitor use 

in this area, resulting in a decrease of vegetation trampling. Overall, these actions would result in a 

local, long-term, minor, beneficial impact on plant communities and wetlands in Wawona. 

Wawona Campground. Facilities actions at the Wawona Campground would involve removal of 

32 sites that are either within the 100-year floodplain or in culturally sensitive areas. This would reduce 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-262 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

visitor use in this area, resulting in a decrease of vegetation trampling. Overall, these actions would 

result in a local, long-term, minor, beneficial impact on plant communities and wetlands in Wawona. 

Segments 5, 6, 7 and 8 Impact Summary: Actions to protect and enhance river values within 

Segments 5, 6, 7 and 8 under Alternative 2 would result in the restoration of 52 acres of vegetation, 

resulting in long-term, segmentwide, major, beneficial impacts on vegetation and wetlands. Actions to 

manage visitor use and facilities would result in long-term, local, minor, beneficial impacts to 

vegetation and wetlands. 

Summary of Impacts from Alternative 2: Self-reliant Visitor Experiences and Extensive 

Floodplain Restoration 

Alternative 2 would restore up to approximately 347 acres of vegetation, including 47.97 acres of 

wetlands, as a result of actions common to Alternatives 2-6 and those specific to Alternative 2. Actions 

to manage visitor use and facilities would result in the loss of 32.37 acres of vegetation and 2.87 acres of 

wetlands as a result of actions specific to Alternative 2. 

Past development and human activity in the Merced River corridor have in some cases adversely 

affected vegetation communities and regional vegetation patterns. Actions associated with Alternative 2 

are expected to have corridorwide, long-term, major, beneficial impacts on vegetation in the Merced 

River corridor. Restoration actions associated with Alternative 2 would restore meadow and riparian 

areas, improve and restore hydrologic function, and restore ecological integrity throughout the river 

corridor; remove and restore informal trails; and direct the public onto established trails and river 

access points. This is part of a comprehensive strategy to reduce existing adverse impacts on meadow, 

wetland, and riparian vegetation. Existing natural resource management actions, such as removal of 

nonnative invasive plants, would continue. Adverse effects from these actions would be local, shortterm, and minor or negligible. Notable actions the NPS would implement under Alternative 2 include 

 restricting recreational use of rivers and riverbanks to reduce riverbank erosion 

 removing, restoring, relocating, or repurposing park facilities to efficiently utilize park 

facilities and reduce the built environment within the park; some facilities would be built to 

accommodate visitors or employees 

 managing total visitors to the park and visitor demands for day parking space, lodging, and 

camping space 

 removing facilities within the 100-year floodplain of the Merced River and restoring 

riverbanks, meadows, and riparian habitat 

 enhancing meadow, riparian, and river hydrologic function, complexity, and connectivity 

 improving the free flow, complexity, and water quality of the Merced River 

Generally, Alternative 2 is focused on intensive restoration of meadow, riparian, and riverbank 

habitats in Yosemite Valley (Segment 2), by emphasizing day use of the Valley over overnight stays; 

removing many facilities that are located in the 100-year floodplain and are jeopardized by flood; 

repurposing park facilities to improve efficiency of use; and providing adequate lodging, camping, and 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 2 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-263

parking space for visitors and employees. Adverse effects from these actions would be associated with 

the active construction or restoration phase, and would be local, short-term, and minor or negligible. 

Were all of these measures to be combined, the long-term effect would be a major, corridorwide, 

beneficial impact on vegetation communities as habitats are restored and fragmentation and edge 

effects reduced. These effects would be most pronounced in areas of high human use, such as 

Yosemite Valley and Wawona (Segments 2 and 7). 

Cumulative Impacts from Alternative 2: Self-reliant Visitor Experiences and Extensive 

Floodplain Restoration 

The past, present, and reasonably foreseeable plans and projects that could have a cumulative impact 

on vegetation resources are the same as those listed under the No Action Alternative. Alternative 2 

would result in segmentwide, long-term, minor to moderate, beneficial impacts on vegetation 

communities within the Merced River corridor. These actions are focused on restoring and improving 

aquatic, meadow, and riparian habitat quality within the Merced River corridor. The past, present, and 

future actions in the region would have varying effects on vegetation and wetlands, with some projects 

restoring or enhancing vegetation and wetlands, and many others resulting in the loss or decline of 

vegetation and wetlands. For projects that would result in the loss of wetland features regulated under 

section 404 of the CWA, losses would be typically compensated at a ratio of 1:1 (no net loss). 

Compensation typically occurs through creation or enhancement of wetlands, either on-site or at a 

designated mitigation bank. However, even with these protections in place, wetlands may be lost over 

time through unregulated activities or negatively impacted through nonpoint source pollution, 

nonnative species, and changes in surface and subsurface hydrology over time. 

The actions under Alternative 2 would have long-term, beneficial effects on vegetation and wetlands, 

including vegetation-related ORVs, within the Merced River corridor. However, in relation to past, 

present, and reasonably foreseeable future actions throughout the Sierra Nevada and larger region 

(e.g., introduction and spread of nonnative species, direct displacement of vegetation by structures), 

the actions under Alternative 2 would have a minimal beneficial effect. Overall, cumulative actions on 

vegetation and wetlands would result in long-term, minor, adverse effects on regional vegetation 

patterns. 

Environmental Consequences of Alternative 3: Dispersed Visitor Experiences and 

Extensive Riverbank Restoration 

Segment 1: Merced River above Nevada Fall 

Impacts of Actions to Protect and Enhance River Values 

Under Alternatives 3, preliminary grazing capacities for the Merced Lake East Meadow would be 

developed. When the meadow recovers, administrative grazing at established capacities would be 

allowed. The meadow would be monitored annually for five years, and use levels would be adapted as 

needed. This adaptive management of grazing in the meadow would help protect meadow vegetation 

from the effects of high levels of grazing by reducing the level of vegetation trampling by 

administrative pack stock and reducing the dispersal of manure and roll pits, and would benefit habitat 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-264 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

connectivity and meadow hydrology. These actions would result in long-term, local, minor beneficial 

impacts to vegetation. 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Several actions related to management of visitor use and facilities would have the potential to affect 

vegetation and wetlands in Segment 1 under Alternative 3. Visitation within Segment 1 would be reduced 

through a decrease in the Little Yosemite Valley trailhead quota (from 150 to 75), conversion of the 

Merced Lake High Sierra Camp, and wilderness campground modifications. Under Alternative 3, there 

would be a 100% reduction in the Merced River corridor’s wilderness lodging units. All 60 units and 

associated facilities at the Merced Lake High Sierra Camp would be removed, resulting in approximately 

11 acres of meadow and subalpine restoration. The area would be used as a temporary pack camp for up 

to 15 people. The park would reduce the total number of designated campsites within the corridor’s 

wilderness. This change would result primarily from the decrease in designated camping in Little 

Yosemite Valley Areas either closed or converted to dispersed camping would be restored to natural 

conditions, including restoration of native vegetation communities. 

These restoration management actions would improve hydrologic function and restore ecological 

integrity of the Merced River corridor in Segment 1 and associated plant communities and wetlands. 

Overall, these actions would result in a local, long-term, minor, beneficial impact on plant 

communities and wetlands in Segment 1. 

Merced Lake High Sierra Camp. The actions in the Merced Lake High Sierra Camp area proposed 

under Alternative 3 involve the conversion of the area to designated Wilderness, removal of all 

infrastructure from the Merced Lake High Sierra Camp, and use of the former camp area as a 

temporary stock camp. As discussed for Alternative 2, these actions would result in a local, long-term, 

minor, beneficial impact on plant communities and wetlands in Segment 1by reducing effects on 

vegetation communities from concentrated visitor use. 

Segment 1 Impact Summary: Actions to manage visitor use and facilities within Segment 1 under 

Alternative 3 would have local, long-term, minor, beneficial impacts on plant communities and 

wetlands along the corridor. 

Segment 2: Yosemite Valley 

Impacts of Actions to Protect and Enhance River Values 

Ecological management actions that would occur within Segment 2 under Alternative 3 in addition to 

those common to Alternatives 2-6 include measures to restore and protect meadows, riparian habitat, 

and areas within the 100-year floodplain of the Merced River. Some of these actions are similar or 

identical to those proposed for Alternative 2. Projects proposed in Segment 2 to protect and enhance 

river values involve removal of buildings from the Yosemite Lodge area; restoration of 10.9 acres of 

riparian habitat at the former Yosemite Lodge units and cabins; rerouting the Valley Loop Trail 

through Slaughterhouse Meadow out of wetlands and meadows to an upland area; moving 780 feet of 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 3 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-265

the Valley Loop Trail out of Bridalveil Meadow; and removing several buildings at Yosemite Lodge out 

of the 100-year floodplain and restoring the area. 

Habitat restoration actions in Segment 2 under Alternative 3 are displayed in Figures 9-21 through 

9-24. The types of habitat that would be affected by these restoration actions in Segment 2, as well as 

the types of habitat that would be enhanced or restored, are summarized in tables 9-22 and 9-23. A 

total of 230 acres of vegetation would be restored in Segment 2, including 46.74 acres of wetlands (this 

includes restoration actions common to Alternatives 2-6). 

Restoration of these areas would prevent further riverbank erosion, provide hydrologic connectivity for 

meadows and riparian habitats, reduce vegetation trampling, enhance the hydrologic function within the 

2–10 year floodplains, enhance water quality, increase the amount of wildlife habitat, increase 

productivity within riparian and aquatic ecosystems, and reduce human presence and human-related 

impacts. 

These restoration management actions would improve the hydrologic function and restore the 

ecological integrity of plant communities and wetlands in the Merced River corridor in Segment 2, 

address ongoing and future impacts on park resources and infrastructure, and manage visitor use and 

development along the river corridor. These actions would be part of a comprehensive strategy to reduce 

existing adverse impacts on meadow and riparian vegetation. Overall, these actions would result in a 

segmentwide, long-term, moderate, beneficial impact on plant communities and wetlands in Segment 2. 

Biological Resource Actions. 

Yosemite Valley Campgrounds: Under Alternative 3, specific restoration actions to enhance the 

river’s biological values in Segment 2 include removing all campsites within 150 feet of the bed and 

banks of the Merced River and restoring 12 acres of floodplain/riparian habitat, and designating river 

access at the North Pines Campground. Restoration of riparian habitat throughout Yosemite Valley 

would result in segmentwide, long-term, moderate, beneficial impacts to vegetation and wetlands. 

El Capitan Meadow: In addition to actions common to Alternatives 2-6, the NPS would use 

restoration fencing and signing to designate appropriate meadow access points, remove all informal 

trails in sensitive and frequently inundated areas and in areas that trails incise meadow and promote 

habitat fragmentation. Restoration of El Capitan Meadow and rerouting or removal of informal trails 

would result in local, long-term, minor to moderate, beneficial impacts on vegetation and wetlands 

from reduction of trampling from foot traffic that causes habitat fragmentation. 

Ahwahnee Meadow: Similar to Alternative 2, specific actions under Alternative 3 in Segment 2 to 

enhance the river’s biological values at the Ahwahnee Meadow include: rerouting or removing trails 

which traverse wetlands in the Ahwahnee meadow and consolidating trail use with the Housekeeping 

Footbridge trail where possible; removing 900 feet of Northside Drive and relocating the bike path to 

the south of Ahwahnee Meadow; and restoring meadow contours and native vegetation. Meadow 

restoration, trail rerouting and removal, and removal of a portion of Northside Drive would result in 

local, long-term, moderate, and beneficial impacts on vegetation and wetlands at the Ahwahnee 

Meadow as wetland fragmentation and vegetation trampling is reduced, and wetland connectivity to 

the river is enhanced. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-266 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

TABLE 9-22: SEGMENT 2 VEGETATION RESTORATION UNDER ALTERNATIVE 3a

Current Vegetation Acres 

Current 

Habitat Type Acres

Proposed Future 

Habitat Type 

Acres Restored 

or Enhanced 

Urban/Developed 2 Barren 2 

Meadow 21 

Intermittently to seasonally 

flooded meadow 14 

Meadow 17 

Semi-permanently to 

permanently flooded meadow 3 

Sparsely vegetated 

undifferentiated 2 Sparsely vegetated 2 

Black cottonwood temporarily 

flooded forest alliance 1 

Lower montane 

broadleaf 16 Lower montane broadleaf 16 California black oak forest 

alliance 7 

California black oak /(bracken 

fern) forest mapping unit 8 

Douglas-fir-(White fir-incense 

cedar-Pondera pine) forest 

mapping unit 

1 

Lower montane 

needleleaf 68 

A mosaic of meadow, 

black oak, and open 

canopy coniferous 

forest 

68 

Ponderosa pine woodland 

alliance 1 

Ponderosa pine-incense cedar 

forest alliance 20 

Ponderosa pine-incense 

cedar-(California black oakcanyon live oak) forest 

superassociation 

46 

Urban/Developed 7 Barren 7 

Riparian & floodplain: 

cottonwood, willow, 

mix of upland 

deciduous & 

coniferous forest 

105 

Black cottonwood 

temporarily flooded forest 

alliance 

1 Lower montane 

broadleaf 1 

Ponderosa pine-incense cedar 

forest alliance 45 

Lower montane 

needleleaf 97 

Ponderosa pine-incense 

cedar-(California black oakcanyon live oak) forest 

superassociation 

52 

Douglas-fir-(White fir-incense 

cedar-Pondera pine) forest 

mapping unit 

1 

Ponderosa pine-incense cedar 

forest alliance 8 

Lower montane 

needleleaf 20 

Riparian: cottonwood, 

willow, mix of upland 

deciduous & 

coniferous forest 

20 Ponderosa pine-incense 

cedar-(California black oakcanyon live oak) forest 

superassociation 

11 

Total 230 230 230 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 
N or th Pines

C ampgr o und

R

Stoneman

Bridge

L ower Pines

C ampground

Stoneman

M eadow

C lark's

Bridge

B ackpackers

C ampground

Ahwahnee

Bridge

Sugar Pine

Bridge

Ahwahnee H otel

H istoric L andmark

H appy

Isles Bridge

H appy Isles

Nature C enter

se

U pper Pines

C ampgr o und

H ousekeeping

C amp

C amp C urry V illage

Stock

Bridge

H ousekeeping

C amp Bridge

H appy

Isles Fen

Sou hs t di e Dr vi e

L eC onte M emorial L odge

H istoric L andmark

M erced R I ver

N orthside D rive

Stables A rea

0 0.125 0.25

Miles

Existing Vegetation and Infrastructure

Surfaced AreaBarrenLower Montane BroadleafLower Montane NeedleleafMeadowWaterRetain BuildingCampgroundRecreational Segment Corridor Classification

Habitat Restoration Actions

Bridge Removal; Infrastructure RemovalDump Station RemovalRiver AccessRemove BuildingRemove RoadBlack Oak RestorationMeadow RestorationRiparian RestorationRiparian and Floodplain Restoration

BoardwalkRemove informal trailBrush layerFill ditchFill removalNew fencingRemove pipeKeep riprap and plantRemove riprap and bioengineerRemove riprap and revegetateRoad removal; Trail removalRevegetate

Merced River Comprehensive Management Plan and EIS . 210436

Figure 9-21

Curry Village Area: Alternative 3 Habitat Restoration Actions

and Select Facilities Actions

SOURCE: NPS, 1997, 2011, 2012

Map Area

Segment

4

Segment

3

Segment

2 Segment 1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment

Curry Village Impact Area
Bridge

Sentinel

Merced R iver

R oyal Arch C reek

BridgeStoneman

C ampground

L ower Pines

M eadow

Stoneman

L ost A rrow Drive

L ost A rrow D rive

Ahwahnee

Bridge

Arch C ascadeR oyal

Village Drive

H ousekeeping

C amp

Superintendent's

Bridge

C amp BridgeH ousekeeping

walk

N orths di e D rive

N

orthside

Drive

R angers' C lub

H istoric L andmark

C hapelYosemite Valley

T he A hwahnee H otel

H istoric L andmark

Yo sem ite V i llage

N orthside D rive

Southside D rive

Oak L ane

Sentinel C rossover

Tecoya R oad

Tenaya W

ay

C amp 6 R oad

C edar L ane

a C st el il C Cff r uo t

Bou dl er L na e

Ahwahnee R oad

C ook's

M eadow

M eadow

Ahwahnee

M eadow

Sentinel

Existing Vegetation and Infrastructure

Recreational Segment Corridor ClassificationRetain BuildingCampgroundWaterMeadowLower Montane NeedleleafLower Montane BroadleafBarrenSurfaced Area

Habitat Restoration Actions

Road mitigation

Riparian and Floodplain RestorationRiparian RestorationMeadow RestorationBlack Oak RestorationRemove RoadRemove BuildingRiver AccessBridge Removal; Infrastructure Removal

RevegetateRoad removal; Trail removalRemove riprap and revegetateRemove riprap and bioengineerKeep riprap and plantNo Action for riprapNew fencingFill removalFill ditchBrush layerRemove informal trail

Merced River Comprehensive Management Plan and EIS . 210436

Figure 9-22

Yosemite Village Area: Alternative 3 Habitat Restoration Actions

and Select Facilities Actions

SOURCE: NPS, 1997, 2011, 2012

0 0.125 0.25

Miles

Map Area

Segment

4

Segment

3

Segment

2 Segment

1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment

Camp 6 & Yosemite Village Impact Area
Camp 4

Historic Site

Yosemite Lodge

Sentinel

Beach

Leidig

Meadow

Swinging

Bridge

Yosemite Lodge Road

Nor ht s di e Dr vi e

Sou 

Wahhoga

Merced RIver

Sentinel Beach

Picnic Area

Swinging Bridge

Picnic Area

Lower Yosemite

Fall Picnic Area Yosemite Lodge & Camp 4 Impact Area

Existing Vegetation and Infrastructure

Surfaced Area

Barren

Lower Montane Broadleaf

Lower Montane Needleleaf

Meadow

Water

Retain Building

Campground

Recreational Segment Corridor Classification

Habitat Restoration Actions

River Access

Remove Building

Black Oak Restoration

Meadow Restoration

Riparian Restoration

Riparian and Floodplain Restoration

Road mitigation

Boardwalk

Remove informal trail

New fencing

No Action for riprap

Keep riprap and plant

Remove riprap and bioengineer

Remove riprap and revegetate

SOURCE: NPS, 1997, 2011, 2012
Cathedral Beac

Bridge

El Capitan

Pohono

Bridge

UV140

|ÿ41

Northside Drive

El

Capitan

Leaning

Tower

Cathedral

Rocks

Cathedral

Spires

Meadow

El Capitan

Meadow

Bridalveil

Slaughterhouse

Meadow

Trailhead

Pohono

) ) )

Merced River

Cathedral Beach

Picnic Area

Wawona Road

El Capitan Trail 

Yosemite Lodge & Camp 4 

Existing Vegetation and Infrastr

Recreational Segment Cor

Campground

Retain Building

Water

Meadow

Lower Montane Needlelea

Lower Montane Broadleaf

Barren

Surfaced Area

Map Area

Segment

4

Segment

3

Segment

2 Segment

1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment

SOURCE: NPS, 1997, 2011, 2012
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 3 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-271

TABLE 9-23: SEGMENT 2 WETLAND RESTORATION UNDER ALTERNATIVE 3 

Wetland Type Acres 

Segment 2 

Palustrine Emergent 19.64 

Palustrine Forested 25.74 

Palustrine Scrub Shrub 1.36 

Total amount of wetlands restored 46.74 

SOURCE: NPS 2012c 

Stoneman Meadow: Like Alternative 2, under Alternative 3 the park would restore Stoneman 

Meadow by removing 1,335 feet of Southside Drive and re-aligning the road through the Boys Town 

area. The Orchard Parking Lot would be redesigned to promote water flow and improve meadow 

health by increasing drainage from the cliff walls to Stoneman Meadow. The meadow boardwalk 

would be extended over wet areas to Curry Village (up to 275 feet). Restoration of Stoneman Meadow 

and protection of sensitive wetland habitat would result in local, long-term, major beneficial impacts 

on vegetation and wetlands. 

Former Upper and Lower Rivers Campgrounds: Specific actions to enhance biological values of the 

Merced River at the Former Upper and Lower Rivers Campgrounds in Alternative 3 are similar to 

Alternative 2, which include restoring 30 acres of the 10-year floodplain. Restoration of the Former 

Upper and Lower Rivers Campgrounds would result in local, long-term, major beneficial impacts on 

vegetation and wetlands. 

These restoration management actions would improve hydrologic function and restore ecological 

integrity of the Merced River corridor in Segment 2 and associated plant communities and wetlands, 

address ongoing and future impacts on park resources and infrastructure, and manage visitor use and 

development along the river corridor. These actions would be part of a comprehensive strategy to 

reduce existing adverse impacts on meadow and riparian vegetation. Overall, these actions would 

result in a segmentwide, long-term, moderate to major beneficial impact on plant communities and 

wetlands in Segment 2. 

Hydrologic/Geologic Resource Actions. Specific projects to protect and enhance the river’s 

hydrologic and geologic values that would occur within Segment 2 under Alternative 3 include: 

relocating unimproved Camp 6 parking; removing Stoneman, Ahwahnee and Sugar Pine bridges; and 

restoring these areas to natural conditions. These actions would result in enhanced channel free flow, 

increased channel complexity, increased streambank stability, and restored riparian habitat 

throughout the segment. Overall these measures would improve the free-flowing condition of the river 

and restore the ecological integrity of Yosemite Valley riparian habitats, resulting in segmentwide, 

long-term, moderate beneficial impacts on plant communities and wetlands in Segment 2. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-272 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Alternative 3 would reduce the maximum daily visitation allowed in Yosemite Valley from current 

levels to allow for increased resource restoration and reduce crowding and congestion. Actions to 

manage visitor use and facilities under Alternative 3, specifically those concerning vehicle access and 

number of overnight accommodations, would result in a 37% decrease in daily Yosemite Valley 

visitation, from approximately 20,900 to 13,200. Day use visitation would decrease by 43%, while 

overnight visitation would decrease by 23%. Under Alternative 3, there would be a net reduction in 

Yosemite Valley lodging units. This is largely due to the removal of units from Housekeeping Camp, 

Curry Village, and Yosemite Lodge. The park would increase the total number of campsites within the 

Valley. This change is largely due to new campsite development east of Camp 4, west of Backpackers 

Campground, and in the Upper Pines Loop Addition. 

Actions to significantly limit day use activities, overnight capacities, and day parking would effectively 

reduce the built environment and human presence within the Valley. Restoration of habitat following 

the removal of facilities and parking lots would increase the extent and contiguity of plant 

communities and wetlands; limiting day use activities and roadside parking would reduce impacts on 

sensitive habitats, such as riparian woodland and wet meadows; and reducing overnight capacities 

would reduce human pressures on vegetation and wetlands in general. 

Relocation of facilities to other locations within the corridor could have long-term, negligible to 

moderate, adverse effects on vegetation, depending on site-specific conditions and project design. 

Local, minor to moderate, short-term, adverse effects could occur from construction and demolition 

of facilities along the Merced River. Vegetation that is removed under Alternative 3 would not 

substantially fragment existing native vegetation communities, reduce species diversity, or 

substantially reduce the overall size or quality of native plant communities in Yosemite Valley, as new 

construction would primarily occur in or adjacent to previously disturbed locations or in more 

resilient, upland habitat. Wetlands would be avoided during construction activities. Adherence to 

proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as 

applicable (see Appendix C), and avoidance of the removal of vegetation where possible, would reduce 

short-term impacts to minor and adverse. Overall, these actions would result in local, short-term, 

minor, adverse impacts on plant communities in Yosemite Valley. 

The overall reduction in infrastructure, lodging units, and campsites and subsequent restoration under 

Alternative 3 would benefit vegetation communities in Yosemite Valley in the long-term. These 

restoration management actions would improve hydrologic function and restore ecological integrity of 

the Merced River corridor in Segment 2 and associated plant communities and wetlands, address 

ongoing and future impacts on park resources and infrastructure, and manage visitor use and 

development along the river corridor. These actions would be part of a comprehensive strategy to 

reduce existing adverse impacts on meadow and riparian vegetation. Overall, these actions would 

result in a segmentwide, long-term, moderate, beneficial impact on plant communities and wetlands in 

Segment 2. 

Curry Village & Campgrounds. Actions under Alternative 3 in Segment 2 related to managing visitor 

use and facilities at Curry Village include the reorganization of Curry Village and the rerouting of 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 3 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-273

South Side Drive at Boys Town. Construction activities at Curry Village would result in direct 

temporary and permanent losses of native vegetation and wetlands as well as the redevelopment of 

existing developed areas (table 9-24). Outside of previously developed areas, impacts to vegetation 

would primarily occur in lower montane coniferous forest and, to a much lesser extent, meadow. 

Losses would occur through vegetation clearing, grading, site development or other surface 

disturbance (e.g., driving over vegetation). As shown in table 9-24 below, only a small percentage of 

these vegetation communities would be affected by the facility actions at Curry Village. Impacts to 

meadow habitat would occur in a small meadow area currently disconnected from the larger 

Stoneman Meadow to the north by Happy Isle Loop Road. In addition, vegetation communities at 

Curry Village are adjacent to already developed areas, and therefore currently experience high levels 

of visitation and human-related impacts such as vegetation trampling and soil compaction. Therefore, 

losses of vegetation communities, while long-term, would be local, adverse and minor. 

TABLE 9-24: VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR USE AND 

FACILITIES AT CURRY VILLAGE & CAMPGROUNDS – ALTERNATIVE 3 

Vegetation/Wetland Type Acres 

Percent of Vegetation/Wetland 

Type Affected in Segmenta

Segment 2 

Meadow 0.03 <0.1% 

Lower Montane Coniferous 6.35 <0.1% 

Redevelopmentb 1.97 N/A 

Wetland (Palustrine Emergent) 0.04 <0.1% 

Wetland (Riverine Intermittent) 0.02 <0.1% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 

Direct impacts to vegetation, including trampling or removal of rooted vegetation, would cause a 

reduction of the total numbers of plants and/or a reduction or loss of total area, diversity, vigor, 

structure, or function of vegetative habitat. Direct impacts could also include decrease plant vigor or 

health from reduced water availability or dust accumulation on photosynthetic surfaces. 

Vegetation that would be removed at Curry Village under Alternative 3 would not substantially 

fragment existing native vegetation communities, reduce species diversity, or substantially reduce the 

overall size or quality of native plant communities in Yosemite Valley, as new construction would 

primarily occur in or adjacent to previously disturbed locations or in more resilient upland habitat. 

Wetlands would be avoided during construction activities. Adherence to proposed mitigation 

measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as applicable (see 

Appendix C), and avoidance of the removal of vegetation where possible, would reduce impacts to 

local, long-term, minor and adverse. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-274 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Construction activities at Curry Village would result in direct, permanent losses of federally protected 

wetlands. Impacts to wetlands would occur in palustrine emergent wetlands associated with Stoneman 

Meadow and intermittent channels flowing through the area. Approximately 0.06 acres of potentially 

jurisdictional wetland features would be directly and permanently impacted by the proposed actions 

under Alternative 3. Losses to these wetlands would occur through site clearing, filling, grading, and 

subsequent development. Construction activities may also generate indirect impacts to wetlands 

including potential modifications to flow, circulation, hydroperiod, or other aspects of the hydrologic 

regime, and increases in sedimentation due to ground disturbance associated with construction. 

However, post-construction, temporarily impacted areas would be restored. Wetlands that cannot be 

avoided and would be permanently filled must be compensated to result in “no net loss” of wetlands. 

Adherence to proposed mitigation measures MM-HYD-1, MM-VEG-1, and MM-VEG-4 through 

MM-VEG-7, as applicable (see Appendix C), and avoidance of wetlands during construction where 

possible, would reduce impacts to wetlands to local, long-term, minor and adverse. 

Camp 6 and Yosemite Village. Actions under Alternative 3 in Segment 2 related to managing visitor 

use and facilities at Camp 6 and Yosemite Village include measures to formalize and relocate parking 

facilities and Northside Drive outside the dynamic 10-year floodplain. The Camp 6/Village Center 

Parking Area would be formalized to include 550 designated parking spaces by redeveloping part of 

the current administrative footprint. In addition, 100 parking spaces would be added at Yosemite 

Village. Northside Drive would be rerouted south of the parking areas and north of the 10-year 

floodplain. Fill material would be removed from the floodplain and the area would be restored to 

meadow and floodplain ecosystems. Expanded parking areas and new road construction activities at 

Yosemite Village would result in direct temporary and permanent losses of native vegetation and 

wetlands (see table 9-25) as well as redevelopment of existing disturbed areas. 

TABLE 9-25: VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR USE AND 

FACILITIES AT CAMP 6 AND YOSEMITE VILLAGE – ALTERNATIVE 3 

Vegetation/Wetland Type Acres 

Percent of 

Vegetation/Wetland Type 

Affected in Segmenta

Segment 2 

Lower Montane Coniferous 9.03 0.1% 

Lower Montane Broadleaf 1.37 <0.1% 

Redevelopmentb 11.55 N/A 

Wetland (Palustrine Emergent) 0.77 0.3% 

Wetland (Palustrine Forested) 1.52 1.3% 

Wetland (Riverine Intermittent) 0.35 0.2% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 3 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-275

As noted in table 9-25, over half of the area affected by the above actions would occur at sites that area 

already developed. Outside of previously developed areas, impacts to vegetation would occur entirely 

in lower montane broadleaf forest and lower montane coniferous forest; these types are among the 

most dominant native vegetation communities in Segment 2. Losses to these communities would occur 

through vegetation clearing, grading, site development or other surface disturbance (e.g., driving over 

vegetation). As shown in table 9-25, only a small percentage of these vegetation communities would be 

impacted by the actions at Camp 6 and Yosemite Village. In addition, potentially affect vegetation 

communities are adjacent to already developed areas, and therefore experience high levels of visitation 

and human-related impacts such as vegetation trampling and soil compaction. Therefore, losses of 

vegetation communities, while long-term, would be local, adverse and minor. 

Vegetation that would be removed at Camp 6 and Yosemite Village under Alternative 3 would not 

substantially fragment existing native vegetation communities, reduce species diversity, or substantially 

reduce the overall size or quality of native plant communities in Yosemite Valley, as new construction 

would primarily occur in or adjacent to previously disturbed locations or in more resilient upland 

habitat. Adherence to proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 

through MM-VEG-7, as applicable (see Appendix C), and avoidance of the removal of vegetation 

where possible, would reduce impacts to local, long-term, minor and adverse. 

The rerouting of Northside Drive outside the 10-year floodplain would result in the restoration of 

floodplain and meadow habitats. As discussed under the Impacts of Actions to Protect and Enhance 

River Values section above, this restoration management action would improve hydrologic function 

and restore ecological integrity of the Merced River corridor in Segment 2 and associated plant 

communities. Overall, this action would result in a localized, long-term, moderate, beneficial impact on 

plant communities and wetlands in Segment 2. 

Parking areas and new road construction activities at Camp 6 and Yosemite Village would result in 

direct, permanent losses of federally protected wetlands. Impacts to wetlands would occur in 

palustrine emergent wetlands located adjacent to the Northside Drive and Sentinel Crossover 

intersection, palustrine forested wetlands associated with the Merced River, and intermittent channels 

flowing through the area. Approximately 2.64 acres of potential jurisdictional wetland features would 

be directly and permanently impacted by proposed actions under Alternative 3. Losses to these 

wetlands would occur through site clearing, filling, grading, and subsequent development. 

Construction activities may also generate indirect impacts to wetlands including potential 

modifications to flow, circulation, hydroperiod, or other aspects of the hydrologic regime, and 

increases in sedimentation due to ground disturbance associated with construction. However, postconstruction, temporarily impacted areas would be restored. Wetlands that cannot be avoided and 

would be permanently filled must be compensated to result in “no net loss” of wetlands. Adherence to 

proposed mitigation measures MM-HYD-1, MM-VEG-1, and MM-VEG-4 through MM-VEG-7, as 

applicable (see Appendix C), and avoidance of wetlands during construction where possible, would 

reduce impacts to wetlands to local, long-term, minor and adverse. 

Yosemite Lodge and Camp 4. Actions under Alternative 3 in Segment 2 related to managing visitor use 

and facilities at Yosemite Lodge and Camp 4 include: the removal of old and temporary housing at 

Highland Court and the Thousands Cabins; the construction of two new concessioner housing areas and 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-276 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

the construction of 78 employee parking spaces; redevelopment west of Yosemite Lodge to provide an 

additional 150 day use parking spaces and area for 15 tour buses; relocation of existing tour bus drop off 

area to Highland Court to provide 3 bus loading/unloading spaces; and the relocation of the pedestrian 

crossing at Northside Drive and Yosemite Lodge Drive to alleviate pedestrian/vehicle conflicts. 

Like other proposed facility projects, construction activities at Yosemite Lodge would result in direct 

temporary and permanent losses of native vegetation and wetlands as well as the redevelopment of 

existing disturbed areas (see table 9-26). Impacts to vegetation would occur entirely in lower montane 

coniferous forest, the dominant natural vegetation community in Segment 2. Losses would occur 

through vegetation clearing, grading, site development or other surface disturbance (e.g., driving over 

vegetation). As shown in table 9-26, only a small percentage of this vegetation community would be 

impacted. In addition, potentially affected vegetation is adjacent to already developed areas, and 

therefore experience high levels of visitation and human-related impacts such as vegetation trampling 

and soil compaction. Therefore, losses of vegetation communities, while long-term, would be local, 

adverse and minor. 

TABLE 9-26: VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR USE AND 

FACILITIES AT YOSEMITE LODGE AND CAMP 4 – ALTERNATIVE 3 

Vegetation/Wetland Type Acres 

Percent of 

Vegetation/Wetland Type 

Affected in Segmenta

Segment 2 

Lower Montane Coniferous 14.80 0.2% 

Lower Montane Broadleaf 0.08 <0.1% 

Redevelopmentb 3.69 N/A 

Wetland (Riverine Intermittent) 0.03 <0.1% 

Wetland (Riverine Perennial) 0.02 <0.1% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 

Like other development actions proposed under this alternative, vegetation that would be removed at 

Yosemite Lodge under Alternative 3 would not substantially fragment existing native vegetation 

communities, reduce species diversity, or substantially reduce the overall size or quality of native plant 

communities in Yosemite Valley, as new construction would primarily occur in or adjacent to previously 

disturbed locations or in more resilient upland habitat. Wetlands would be avoided during construction 

activities. Adherence to proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 

through MM-VEG-7, as applicable (see Appendix C), and avoidance of the removal of vegetation 

where possible, would reduce impacts to local, long-term, minor and adverse. 

Construction activities at Yosemite Lodge and Camp 4 would result in direct, permanent losses of 

federally protected wetlands. Impacts to wetlands would occur along the Merced River and in 

intermittent channels flowing through the area. Approximately 0.05 acres of potentially jurisdictional 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 3 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-277

wetland features would be directly and permanently impacted by the proposed actions under 

Alternative 3. Losses to these wetlands would occur through site clearing, filling, grading, and 

subsequent development. Construction activities may also generate indirect impacts to wetlands 

including potential modifications to flow, circulation, hydroperiod, or other aspects of the hydrologic 

regime, and increases in sedimentation due to ground disturbance associated with construction. 

However, post-construction, temporarily impacted areas would be restored. Wetlands that cannot be 

avoided and would be permanently filled must be compensated to result in “no net loss” of wetlands. 

Adherence to proposed mitigation measures MM-HYD-1, MM-VEG-1, and MM-VEG-4 through 

MM-VEG-7, as applicable (see Appendix C), and avoidance of wetlands during construction where 

possible, would reduce impacts to wetlands to local, long-term, minor and adverse. 

In summary, as shown in table 9-27, actions to manage visitor use and facilities would result in the loss 

of 31.66 acres of vegetation primarily located near previously developed areas, resulting in long-term, 

local, minor, adverse impacts these communities. Actions to manage visitor use and facilities would 

result in the loss of 2.75 acres of potentially jurisdictional wetlands. 

TABLE 9-27: SUMMARY OF VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR 

USE AND FACILITIES IN SEGMENT 2 – ALTERNATIVE 3 

Vegetation/Wetland Type Acres 

Percent of 

Vegetation/Wetland Type 

Affected in Segmenta

Segment 2 

Meadow 0.03 <0.1% 

Lower Montane Coniferous 30.18 0.4% 

Lower Montane Broadleaf 1.45 <0.1% 

Redevelopmentb 17.21 N/A 

Wetland 2.75 0.5% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 

Segment 2 Impact Summary: Actions to protect and enhance river values within Segment 2 under 

Alternative 3 would result in the restoration of approximately 230 acres of vegetation and 39.85 acres 

of wetland, resulting in long-term, segmentwide, major, beneficial impacts on vegetation and wetlands. 

Actions to manage visitor use and facilities would result in the loss of 31.66 acres of vegetation 

primarily located near previously developed areas, resulting in long-term, local, minor to moderate, 

adverse impacts these communities. Actions to manage visitor use and facilities would result in the loss 

of 2.75 acres of potentially jurisdictional wetlands. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-278 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Segments 3 and 4: Merced Gorge and El Portal 

Impacts of Actions to Protect and Enhance River Values 

Currently, vehicles park under the dripline of the 38 valley oak trees. This practice compacts soil under 

the trees, affecting root health, water uptake, and soil aeration. Additionally, existing development and 

trampling in the vicinity limits the area where oak seedlings can be recruited. Under Alternative 3, 

valley oaks in El Portal would be enhanced by creating an oak recruitment area of 2.25 acres in Old 

El Portal in the vicinity of the current bulk fuel storage area, including the adjacent parking lots. 

Parking and new building construction within the oak recruitment area would be prohibited. 

Nonnative fill would be removed and soils decompacted. Appropriate native understory plant species 

would be planted. The fuel storage area would be relocated outside of the river corridor. Overall, these 

actions would result in local, long-term, moderate, beneficial impacts on valley oaks in El Portal. 

The types of habitat that would be affected by these restoration actions in Segment 2, as well as the 

types of habitat that would be enhanced or restored, are summarized in tables 9-28 and 9-29. A total 

of 13 acres of vegetation would be restored in Segment 4, including 0.05 acres of wetlands (this 

includes restoration actions common to Alternatives 2-6). 

TABLE 9-28: SEGMENT 4 VEGETATION RESTORATION UNDER ALTERNATIVE 3a

Current Vegetation Acres 

Current 

Vegetation Type Acres

Proposed Future 

Vegetation Type 

Acres Restored 

or Enhanced 

Valley oak woodland alliance 1 Foothill broadleaf 

woodland 1 Valley oak woodland 1 

Sparsely vegetated riverine 

flat 2 Sparsely vegetated 2 Riparian & floodplain: 

cottonwood, willow, 

mix of upland 

deciduous & 

coniferous forest 

12 canyon live oak-(Ponderosa 

pine-incense cedar) forest 

superassociation 

10 Lower montane 

broadleaf 13 

Total 13 13 13 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 

TABLE 9-29: SEGMENT 4 WETLAND RESTORATION UNDER ALTERNATIVE 3 

Wetland Type Acres 

Segment 4 

Palustrine Emergent 0.001 

Palustrine Forested 0.05 

Total amount of wetlands restored 0.05 

SOURCE: NPS 2012c 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 3 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-279

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Under Alternative 3, user capacity is mostly affected by the increase in employee housing at El Portal. 

In Alternative 3, NPS employee housing would be added to Abbieville, El Portal Village Center, and 

Rancheria Flat; employee parking would be added at Rancheria, El Portal, and Abbieville. While all 

new units would be built outside of the 100-year floodplain, they would fall within the river corridor. 

This increase in capacity in El Portal is a function of the decrease in employee housing capacity in the 

valley (Segment 2). The addition of employee housing and park facilities development would increase 

the total built environment within Segment 4. 

Relocation of facilities to other locations within the corridor could have long-term, negligible to 

moderate, adverse effects on vegetation, depending on site-specific conditions and project design. 

Local, minor to moderate, short-term, adverse effects could occur from construction and demolition 

of facilities along the Merced River. Vegetation that is removed under Alternative 3 would not 

substantially fragment existing native vegetation communities, reduce species diversity, or 

substantially reduce the overall size or quality of native plant communities at El Portal, as new 

construction would primarily occur in or adjacent to previously disturbed locations or in more 

resilient, upland habitat. Wetlands would be avoided during construction activities. Adherence to 

proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as 

applicable (see Appendix C), and avoidance of the removal of vegetation where possible, would reduce 

short-term impacts to minor and adverse. Overall, these actions would result in local, short-term, 

minor, adverse impacts on plant communities in El Portal. 

Segments 3 and 4 Impact Summary: Actions to protect and enhance river values within Segments 3 

and 4 would result in the restoration of 13 acres of vegetation and 0.05 acres of wetland, resulting in 

long-term, local, moderate, beneficial impacts on vegetation and wetlands. Actions to manage visitor 

use and facilities would result in short-term, local, minor, adverse impacts to vegetation and wetlands. 

Segments 5, 6, 7, and 8: South Fork Merced River 

Impacts of Actions to Protect and Enhance River Values 

The Wawona Golf Course is located in a former meadow, altering vegetation patterns, compacting 

soils, and interrupting meadow hydrology. Under Alternative 3, the Wawona Golf Course would be 

decommissioned and the area restored to native meadow habitat through recontouring and 

revegetation. These actions would collectively improve meadow and wetland habitat integrity, 

increase the extent of meadows, and enhance contiguity of meadow habitats as well as hydrological 

connectivity between meadow, riparian, and floodplain habitats. Overall, these actions would result in 

a local, long-term, moderate, beneficial impact on plant communities and wetlands in Wawona. 

The types of habitat that would be affected by these restoration actions in Segment 7, as well as the 

types of habitat that would be enhanced or restored, are summarized in table 9-30. A total of 48 acres 

of vegetation would be restored in Segment 7 (this includes restoration actions common to 

Alternatives 2-6). 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-280 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

TABLE 9-30: SEGMENT 7 VEGETATION RESTORATION UNDER ALTERNATIVE 3a

Current Vegetation Acres 

Current 

Habitat Type Acres

Proposed Future 

Habitat Type 

Acres Restored 

or Enhanced 

Urban/Developed 40 Barren 40 

Meadow 41 

Ponderosa pine woodland 

alliance 1 

Lower montane 

needleleaf 1 

Ponderosa pine-incense cedar 

forest alliance 1 

Ponderosa pine woodland 

alliance 1 

Lower montane 

needleleaf 7 

Riparian: cottonwood, 

willow, mix of upland 

deciduous & 

coniferous forest 

7 

Ponderosa pine-incense cedar 

forest alliance 5 

Ponderosa pine-incense cedar-

(California black oak-canyon 

live oak) forest superassociation 

1 

Total 48 48 48 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 

Biological Resource Actions. Specific projects to protect and enhance the river’s biological values 

that would occur within Segment 7 under Alternative 3 include the relocation of stock use campsites 

from sensitive resource areas to Wawona Stables. Overall, this action would result in a local, long-term, 

minor, beneficial impact on plant communities and wetlands in Wawona.

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Under Alternative 3, the operations of the Wawona stables would be eliminated and two stock 

campsites would be relocated to this area from the current Wawona stock camp. The Wawona tennis 

courts would be removed. The area would be restored to natural conditions. Soils would be 

decompacted and the area would be replanted with riparian vegetation. This would reduce visitor use 

in this area, resulting in a decrease of vegetation trampling. Overall, these actions would result in a 

local, long-term, minor, beneficial impact on plant communities and wetlands in Wawona. 

Wawona Campground. Facilities actions at the Wawona Campground would involve removal of 

27 sites that are either within the 100-year floodplain or in culturally sensitive areas. This would reduce 

visitor use in this area, resulting in a decrease of vegetation trampling. Overall, these actions would 

result in a local, long-term, minor, beneficial impact on plant communities and wetlands in Wawona. 

Segments 5, 6, 7 and 8 Impact Summary: Actions to protect and enhance river values within 

Segments 5, 6, 7 and 8 under Alternative 3 would result in the restoration of 48 acres of vegetation, 

resulting in long-term, segmentwide, major, beneficial impacts on vegetation and wetlands. Actions to 

manage visitor use and facilities would result in long-term, local, minor, beneficial impacts to 

vegetation and wetlands. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 3 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-281

Summary of Impacts from Alternative 3: Dispersed Visitor Experiences and Extensive 

Riverbank Restoration 

Alternative 3 would restore approximately 302 acres of vegetation, including 46.79 acres of wetlands, 

as a result of actions common to Alternatives 2-6 in conjunction with actions specific to Alternative 3. 

Actions to manage visitor use and facilities would result in the loss of approximately 31.66 acres of 

vegetation and the permanent loss of 2.75 acres of potentially jurisdictional wetlands as a result of 

actions specific to Alternative 3. 

Past development and human activity in the Merced River corridor have in some cases adversely 

affected vegetation communities and regional vegetation patterns. Actions associated with Alternative 

3 are expected to have corridorwide, long-term, major, beneficial impacts on vegetation in the Merced 

River corridor. Restoration actions associated with Alternative 3 would restore meadow and riparian 

areas, improve and restore hydrologic function, and restore ecological integrity throughout the 

corridor, remove and restore informal trails, and direct the public onto established trails and river 

access points. This is part of a comprehensive strategy to reduce existing adverse impacts on meadow, 

wetland, and riparian vegetation. Existing natural resource management actions, such as removal of 

nonnative invasive plants, would continue. Adverse effects from these actions would be local, shortterm, and minor or negligible. Notable actions the park would implement under Alternative 3 include: 

 restricting recreational use of rivers and riverbanks to reduce riverbank erosion 

 removing, restoring, relocating, or repurposing park facilities to efficiently utilize park 

facilities and reduce the built environment within the park; some facilities would be built to 

accommodate visitors or employees 

 managing total visitors to the park and visitor demands for day parking space, lodging, and 

camping space 

 removing facilities within 150 feet of the Merced River and restoring riverbanks, meadows, 

and riparian habitat 

 enhancing meadow, riparian, and river hydrologic function, complexity, and connectivity 

 improving the free flow, complexity, and water quality of the Merced River 

Generally, Alternative 3 is focused on intensive restoration of meadow, riparian, and riverbank 

habitats in Yosemite Valley (Segment 2); removing many facilities that are located within 150 feet of 

the river and are jeopardized by flood; repurposing park facilities to improve efficiency of use and; 

providing adequate lodging, camping, and parking space for visitors and employees. Adverse effects 

from these actions would be associated with the active construction or restoration phase, and would 

be local, short-term, and minor or negligible. When combined, the long-term effect of all of these 

measures would be a major, corridorwide, beneficial impact on vegetation communities as habitats are 

restored and fragmentation and edge effects reduced. These effects would be most pronounced in 

areas of high human use, such as Yosemite Valley and Wawona (Segments 2 and 7). 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-282 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Cumulative Impacts from Alternative 3: Dispersed Visitor Experiences and Extensive 

Riverbank Restoration 

The past, present, and reasonably foreseeable plans and projects that could have a cumulative impact 

on vegetation resources are the same as those listed under Alternative 1. Alternative 3 would result in 

segmentwide, long-term, minor to moderate, beneficial impacts on vegetation communities within the 

Merced River corridor. These actions are focused on restoring and improving aquatic, meadow, and 

riparian habitat quality within the Merced River corridor. The past, present, and future actions in the 

region would have varying effects on vegetation and wetlands, with some projects restoring or 

enhancing vegetation and wetlands, and many others resulting in the loss or decline of vegetation and 

wetlands. For projects that would result in the loss of wetland features regulated under section 404 of 

the CWA, losses would be typically compensated at a ratio of 1:1 (no net loss). Compensation typically 

occurs through creation or enhancement of wetlands, either on-site or at a designated mitigation bank. 

However, even with these protections in place, wetlands may be lost over time through unregulated 

activities or negatively impacted through nonpoint source pollution, nonnative species, and changes in 

surface and subsurface hydrology over time. 

The actions under Alternative 3 would have long-term, beneficial effects on vegetation and wetlands, 

including vegetation-related ORVs, within the Merced River corridor. However, in relation to past, 

present, and reasonably foreseeable future actions throughout the Sierra Nevada and larger region 

(e.g., introduction and spread of nonnative species, direct displacement of vegetation by structures), the 

actions under Alternative 3 would have a minimal beneficial effect. Overall, cumulative actions on 

vegetation and wetlands would result in long-term, minor adverse effects on regional vegetation patterns. 

Environmental Consequences of Alternative 4: Resource-based Visitor Experiences 

and Targeted Riverbank Restoration 

Segment 1: Merced River above Nevada Fall 

Impacts of Actions to Protect and Enhance River Values 

Under Alternative 4, grazing would be eliminated and administrative pack stock would be required to 

carry pellet feed in Merced Lake East Meadow, as described for Alternatives 2. Beneficial effects to 

vegetation would be the same as described for Alternative 2. 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Several actions related to management of visitor use and facilities would have the potential to affect 

vegetation and wetlands in Segment 1 under Alternative 4. Visitation within Segment 1 would be 

reduced through a decrease in the Little Yosemite Valley trailhead quota (from 150 to 100), closure of 

the Merced Lake High Sierra Camp, and wilderness campground modifications. Under Alternative 4, 

there would be a 100% reduction in the Merced River corridor’s wilderness lodging units. All 60 units 

and associated facilities at the Merced Lake High Sierra Camp would be removed, resulting in the 

restoration of approximately 11 acres of meadow and subalpine habitats. The park would reduce the 

total number of designated backpacker campsites within Wilderness. This change would result 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 4 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-283

primarily from the decrease in designated camping at Little Yosemite Valley Backpackers 

Campground and removal of bear boxes (composting toilet remains). Designated camping at Moraine 

Dome would continue and dispersed camping at the Merced Lake Backpackers Campground would 

be expanded in response to removal of designated campsites, but facilities would be reduced (i.e., flush 

toilets and wastewater system would be replaced with composting toilets and bear boxes removed). 

These restoration management actions would improve hydrologic function and restore ecological 

integrity of the river corridor in Segment 1 and associated plant communities and wetlands. Overall, 

these actions would result in a local, long-term, minor, beneficial impact on plant communities and 

wetlands in Segment 1. 

Merced Lake High Sierra Camp. The actions in the Merced Lake High Sierra Camp area proposed 

under Alternative 4 involve the conversion of the area to designated Wilderness, the closure of the 

Merced Lake High Sierra Camp, and restoration of the former camp area to natural conditions. These 

actions would result in a local, long-term, minor, beneficial impact on plant communities and wetlands 

in Segment 1.by reducing impacts on vegetation communities from concentrated visitor use, overnight 

camping, and presence of infrastructure. 

Segment 1 Impact Summary: Actions to manage visitor use and facilities within Segment 1 under 

Alternative 4 would have local, long-term, minor, beneficial impacts on plant communities and 

wetlands in the river corridor. 

Segment 2: Yosemite Valley 

Impacts of Actions to Protect and Enhance River Values 

Ecological management actions that would occur within Segment 2 under Alternative 4 include 

measures to restore and protect meadows, riparian habitat, and areas within the 100-year floodplain of 

the Merced River. Some of these proposed actions are generally similar or identical those in 

Alternatives 2 and/or Alternative 3. Projects proposed in Segment 2 to protect and enhance river 

values, in addition to actions common to alternatives 2-6 involve rerouting the Valley Loop Trail 

through Slaughterhouse Meadow out of wetlands and meadows to an upland area; restoration of 

10.9 acres of riparian habitat at the former Yosemite Lodge units and cabins; and moving 780 feet of 

the Valley Loop Trail out of Bridalveil Meadow. 

Habitat restoration actions in Segment 2 under Alternative 4 are displayed in figures 9-25 through 

9-28. The types of habitat that would be affected by these restoration actions in Segment 2, as well as 

the types of habitat that would be enhanced or restored, are summarized in tables 9-31 and 9-32. A 

total of 194 acres of vegetation would be restored in Segment 2, including 44.52 acres of wetlands (this 

includes restoration actions common to Alternatives 2-6). 

Restoration of these areas would prevent further riverbank erosion, provide hydrologic connectivity for 

meadows and riparian habitats, reduce vegetation trampling, enhance the hydrologic function within the 

floodplain, enhance water quality, increase the amount of wildlife habitat, increase productivity within 

riparian and aquatic ecosystems, and reduce human presence and human-related impacts. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-284 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

TABLE 9-31: SEGMENT 2 VEGETATION RESTORATION UNDER ALTERNATIVE 4a

Current Vegetation Acres 

Current 

Vegetation Type Acres

Proposed Future 

Vegetation Type 

Acres Restored 

or Enhanced 

Urban/Developed 2 Barren 2 

Meadow 21 

Intermittently to seasonally 

flooded meadow 14 

Meadow 17 

Semi-permanently to 

permanently flooded meadow 3 

Sparsely vegetated 

undifferentiated 2 Sparsely vegetated 2 

Black cottonwood temporarily 

flooded forest alliance 1 

Lower montane 

broadleaf 15 Lower montane broadleaf 15 California black oak forest 

alliance 6 

California black oak /(bracken 

fern) forest mapping unit 8 

Douglas-fir-(White fir-incense 

cedar-Pondera pine) forest 

mapping unit 

1 

Lower montane 

needleleaf 67 

A mosaic of meadow, 

black oak, and open 

canopy coniferous 

forest 

67 

Ponderosa pine woodland 

alliance 1 

Ponderosa pine-incense cedar 

forest alliance 20 

Ponderosa pine-incense 

cedar-(California black oakcanyon live oak) forest 

superassociation 

45 

Black cottonwood temporarily 

flooded forest alliance 1 Lower montane broadleaf 1 

Riparian & floodplain: 

cottonwood, willow, 

mix of upland 

deciduous & 

coniferous forest 

46 

Ponderosa pine-incense cedar 

forest alliance 15 

Lower montane 

needleleaf 45 

Ponderosa pine-incense 

cedar-(California black oakcanyon live oak) forest 

superassociation 

29 

Douglas-fir-(White fir-incense 

cedar-Pondera pine) forest 

mapping unit 

1 

Urban/Developed 4 Barren 4 

Riparian: cottonwood, 

willow, mix of upland 

deciduous & 

coniferous forest 

45 

Ponderosa pine-incense cedar 

forest alliance 25 

Lower montane 

needleleaf 41 Ponderosa pine-incense 

cedar-(California black oakcanyon live oak) forest 

superassociation 

16 

Total 194 194 194 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 
N or th Pines

C ampgr o und

R

Stoneman

Bridge

L ower Pines

C ampground

Stoneman

M eadow

C lark's

Bridge

B ackpackers

C ampground

Ahwahnee

Bridge

Sugar Pine

Bridge

Ahwahnee H otel

H istoric L andmark

H appy

Isles Bridge

H appy Isles

Nature C enter

se

U pper Pines

C ampgr o und

H ousekeeping

C amp

C amp C urry V illage

Stock

Bridge

H ousekeeping

C amp Bridge

H appy

Isles Fen

Sou hs t di e Dr vi e

L eC onte M emorial L odge

H istoric L andmark

M erced R I ver

U pper and L ower

R iver C ampground A rea

N orthside D rive

Stables A rea

0 0.125 0.25

Miles

Existing Vegetation and Infrastructure

Surfaced AreaBarrenLower Montane BroadleafLower Montane NeedleleafMeadowWaterRetain BuildingCampgroundRecreational Segment Corridor Classification

Habitat Restoration Actions

Bridge Removal; Infrastructure RemovalDump Station RemovalRiver AccessRemove BuildingRemove RoadMeadow RestorationRiparian RestorationRiparian and Floodplain Restoration

BoardwalkRemove informal trailBrush layerFill ditchFill removalNew fencingRemove pipeKeep riprap and plantRemove riprap and bioengineerRemove riprap and revegetateRoad removal; Trail removalRevegetate

Merced River Comprehensive Management Plan and EIS . 210436

Figure 9-25

Curry Village Area: Alternative 4 Habitat Restoration Actions

and Select Facilities Actions

SOURCE: NPS, 1997, 2011, 2012

Map Area

Segment

4

Segment

3

Segment

2 Segment 1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment

Curry Village Impact Area
Bridge

Sentinel

Merced R iver

R oyal Arch C reek

BridgeStoneman

C ampground

L ower Pines

M eadow

Stoneman

L ost A rrow Drive

L ost A rrow D rive

Ahwahnee

Bridge

Arch C ascadeR oyal

Village Drive

H ousekeeping

C amp

Superintendent's

Bridge

C amp BridgeH ousekeeping

walk

N orths di e D rive

N

orthside

Drive

R angers' C lub

H istoric L andmark

C hapelYosemite Valley

T he A hwahnee H otel

H istoric L andmark

Yo sem ite V i llage

U pper and L ower

R iver C ampground Area

N orthside D rive

Southside D rive

Oak L ane

Sentinel C rossover

Tecoya R oad

Tenaya W

ay

C amp 6 R oad

C edar L ane

a C st el il C Cff r uo t

Bou dl er L na e

Ahwahnee R oad

C ook's

M eadow

M eadow

Ahwahnee

M eadow

Sentinel

Existing Vegetation and Infrastructure

Recreational Segment Corridor ClassificationRetain BuildingCampgroundWaterMeadowLower Montane NeedleleafLower Montane BroadleafBarrenSurfaced Area

Habitat Restoration Actions

BoardwalkRoad mitigation

Riparian and Floodplain RestorationRiparian RestorationMeadow RestorationBlack Oak RestorationRemove BuildingRiver AccessBridge Removal; Infrastructure Removal

RevegetateRoad removal; Trail removalRemove riprap and revegetateRemove riprap and bioengineerKeep riprap and plantNo Action for riprapNew fencingFill removalFill ditchBrush layerRemove informal trail

Merced River Comprehensive Management Plan and EIS . 210436

Figure 9-26

Yosemite Village Area: Alternative 4 Habitat Restoration Actions

and Select Facilities Actions

SOURCE: NPS, 1997, 2011, 2012

0 0.125 0.25

Miles

Map Area

Segment

4

Segment

3

Segment

2 Segment

1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment

Camp 6 & Yosemite Village Impact Area
Camp 4

Historic Site

Yosemite Lodge

Sentinel

Beach

Leidig

Meadow

Swinging

Bridge

Yosemite Lodge Road

Nor ht s di e Dr vi e

Sou 

Wahhoga

Merced RIver

Sentinel Beach

Picnic Area

Swinging Bridge

Picnic Area

Lower Yosemite

Fall Picnic Area Yosemite Lodge & Camp 4 Impact Area

Existing Vegetation and Infrastructure

Surfaced Area

Barren

Lower Montane Broadleaf

Lower Montane Needleleaf

Meadow

Water

Retain Building

Campground

Recreational Segment Corridor Classification

Habitat Restoration Actions

River Access

Remove Building

Black Oak Restoration

Meadow Restoration

Riparian Restoration

Riparian and Floodplain Restoration

Road mitigation

Boardwalk

Remove informal trail

New fencing

No Action for riprap

Keep riprap and plant

Remove riprap and bioengineer

Remove riprap and revegetate

SOURCE: NPS, 1997, 2011, 2012
Cathedral Beac

Bridge

El Capitan

Pohono

Bridge

UV140

|ÿ41

Northside Drive

El

Capitan

Leaning

Tower

Cathedral

Rocks

Cathedral

Spires

Meadow

El Capitan

Meadow

Bridalveil

Slaughterhouse

Meadow

Trailhead

Pohono

) ) )

Merced River

Cathedral Beach

Picnic Area

Wawona Road

El Capitan Trail 

Yosemite Lodge & Camp 4 

Existing Vegetation and Infrastr

Recreational Segment Cor

Campground

Retain Building

Water

Meadow

Lower Montane Needlelea

Lower Montane Broadleaf

Barren

Surfaced Area

Map Area

Segment

4

Segment

3

Segment

2 Segment

1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment

SOURCE: NPS, 1997, 2011, 2012
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 4 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-289

TABLE 9-32: SEGMENT 2 WETLAND RESTORATION UNDER ALTERNATIVE 4 

Wetland Type Acres 

Segment 2 

Palustrine Emergent 18.36 

Palustrine Forested 24.96 

Palustrine Scrub Shrub 1.20 

Total amount of wetlands restored 44.52 

SOURCE: NPS 2012c 

These restoration management actions would improve the hydrologic function and restore the 

ecological integrity of the plant communities and wetlands in the Merced River corridor in Segment 2, 

address ongoing and future impacts on park resources and infrastructure, and manage visitor use and 

development along the river corridor. These actions would be part of a comprehensive strategy to reduce 

existing adverse impacts on meadow and riparian vegetation. Overall, these actions would result in a 

segmentwide, long-term, moderate, beneficial impact on plant communities and wetlands in segment 2. 

Biological Resource Actions. 

Yosemite Valley Campgrounds: Like Alternative 3, specific restoration actions under Alternative 4 to 

enhance the river’s biological values in Segment 2 include removing all campsites within 150 feet of the 

bed and banks of the Merced River and restoring 12 acres of floodplain/riparian habitat, and designating 

river access at the North Pines Campground. Restoration of riparian habitat throughout Yosemite Valley 

would result in segmentwide, long-term, moderate, beneficial impacts to vegetation and wetlands. 

El Capitan Meadow: In addition to actions common to Alternatives 2-6, Alternative 4 would install 

restoration fencing along the northern perimeter of El Capitan Meadow to designate appropriate 

meadow access points along boardwalks and viewing platforms. Alternative 4 would remove all 

informal trails in sensitive and frequently inundated areas and in areas that trails incise meadow and 

promote habitat fragmentation. Restoration of El Capitan Meadow and rerouting or removal of 

informal trails would result in local, long-term, minor to moderate, beneficial impacts on vegetation 

and wetlands from reduction of trampling from foot traffic that causes habitat fragmentation. 

Ahwahnee Meadow: Specific actions under Alternative 4 in Segment 2 to enhance the river’s biological 

values at the Ahwahnee Meadow include: removing fill in sections of trails that passes through meadow 

and wetland habitats and replace the trails with boardwalk. However, unlike Alternatives 2 and 3, 

Northside Drive and the adjacent bike path would remain under Alternative 4. Hydrological connectivity 

between both sides of Northside Drive would be enhanced by increasing the number of culverts. Trail 

improvement and meadow restoration would result in local, long-term, minor to moderate, and 

beneficial impacts on vegetation and wetlands at the Ahwahnee Meadow as wetland fragmentation and 

vegetation trampling is reduced, and wetland connectivity to the river is enhanced. 

Stoneman Meadow: Like Alternatives 2 and 3, specific actions in Alternative 4 to enhance the 

biological values of the Merced River include restoring Stoneman Meadow by removing 1,335 feet of 

Southside Drive and re-aligning the road through Boys Town area. The Orchard Parking Lot would be 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-290 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

redesigned and engineering solutions would be applied to promote water flow and improve meadow 

health to increase drainage from the cliff walls to Stoneman Meadow. The meadow boardwalk would 

be extended through wet areas to Curry Village (up to 275 feet). Restoration of Stoneman Meadow 

and protection of sensitive wetland habitat would result in local, long-term, minor to moderate, and 

beneficial impacts on vegetation and wetlands. 

Former Upper and Lower Rivers Campgrounds: Specific actions to enhance biological values of the 

Merced River at the Former Upper and Lower Rivers Campgrounds in Alternative 4 include restoring the 

topography of 16.5 acres of the floodplain. While this area is largely undeveloped, Alternative 4 would 

remove remaining asphalt, decompact soils of former roads and campsites re-establish river cut-off 

channels by removing imported fill, place large box culverts under the road to allow water flow, and fence 

and close the riparian zone at former Upper River to protect the riverbank from trampling associated with 

new walk-in campgrounds. Restoration of the Former Upper and Lower Rivers Campgrounds would 

result in local, long-term, minor, and beneficial impacts on vegetation and wetlands. 

These restoration management actions would improve hydrologic function and restore ecological 

integrity of the Merced River corridor in Segment 2 and associated plant communities and wetlands, 

address ongoing and future impacts on park resources and infrastructure, and manage visitor use and 

development along the river corridor. These actions would be part of a comprehensive strategy to reduce 

existing adverse impacts on meadow and riparian vegetation. Overall, these actions would result in a 

segmentwide, long-term, minor to moderate, beneficial impact on plant communities and wetlands in 

Segment 2. 

Hydrologic/Geologic Resource Actions. Specific projects to protect and enhance the river’s 

hydrologic and geologic values that would occur within Segment 2 under Alternative 4 include: 

relocating unimproved Camp 6 parking; placing large wood and constructed logjams along the base of 

Stoneman Bridge; removing the Ahwahnee and Sugar Pine Bridges; and restoring these areas to natural 

conditions. These actions would result in enhanced channel free flow, increased channel complexity, 

increased streambank stability, and restored riparian habitat segmentwide. Overall these measures 

would improve the free-flowing condition of the river and restore the ecological integrity of Yosemite 

Valley riparian habitats, resulting in segmentwide, long-term, moderate beneficial impacts on plant 

communities and wetlands in Segment 2. 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Alternative 4 would reduce the maximum daily visitation allowed in Yosemite Valley from current 

levels to allow for increased resource restoration and reduce crowding and congestion. Actions to 

manage visitor use and facilities under Alternative 4, specifically those concerning vehicle access, 

would result in a 19% decrease in daily Yosemite Valley visitation, from approximately 20,900 to 

17,000. Day use visitation would decrease by nearly 29%. However, due in part to increases in 

campground facilities, overnight visitation would increase by about 7%. Under Alternative 4, there 

would be a net reduction in Valley lodging units. This would be achieved through removal of units 

from Housekeeping Camp and Curry Village. The park would increase the total number of campsites 

within the Valley. This increase would be largely due to the development of new campsites near 

Yosemite Lodge (west) and Camp 4 (east), as well as at Boys Town, Upper Pines Campground, Curry 

Village stables, and the former Upper River and Lower River campgrounds. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 4 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-291

Restoring habitat following the removal of facilities and parking lots would increase the extent and 

contiguity of plant communities and wetlands; limiting day use activities and roadside parking would 

reduce impacts to sensitive habitats, such as riparian woodland and wet meadows; and reducing 

overnight capacities would reduce human pressures on plant communities and wetlands in general. 

Relocation of facilities to other locations within the corridor could have long-term, negligible to 

moderate, adverse effects on vegetation, depending on site-specific conditions and project design. 

Local, minor to moderate, short-term, adverse effects could occur from construction and demolition 

of facilities along the Merced River. Vegetation that is removed under Alternative 4 would not 

substantially fragment existing native vegetation communities, reduce species diversity, or 

substantially reduce the overall size or quality of native plant communities at Yosemite Valley, as new 

construction would primarily occur in or adjacent to previously disturbed locations or in more 

resilient, upland habitat. Wetlands would be avoided during construction activities. Adherence to 

proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as 

applicable (see Appendix C), and avoidance of the removal of vegetation where possible, would reduce 

short-term impacts to minor and adverse. Overall, these actions would result in local, short-term, 

minor to moderate, adverse impacts on plant communities in Yosemite Valley. 

Former Upper and Lower River Campground Area. Construction of new walk-in campgrounds and 

picnic area in undeveloped areas at the former Upper and Lower Campgrounds would preclude the 

ecological restoration of the former riparian/wetland/California black oak complex in the area. 

Fencing along the riverbank would mitigate potential additional trampling damage to riparian areas. 

Construction activities at Upper and Lower River Campground would result in direct, temporary and 

permanent losses of native vegetation as well as the redevelopment of existing developed areas. 

Outside of previously developed areas, impacts to vegetation would occur in lower montane coniferous 

forest. Losses would occur through vegetation clearing, grading, site development or other surface 

disturbance (e.g., driving over vegetation).Losses of vegetation communities, while long-term, would be 

local, adverse and moderate.

Curry Village & Campgrounds. Actions under Alternative 4 in Segment 2 related to managing visitor 

use and facilities at Curry Village include the reorganization of Curry Village; the rerouting of South Side 

Drive at Boys Town; and the construction of a 40-site campground at Boys Town. Construction activities 

at Curry Village would result in direct, temporary and permanent losses of native vegetation and 

wetlands (see table 9-33) as well as the redevelopment of existing developed areas. Outside of previously 

developed areas, impacts to vegetation would occur in lower montane coniferous forest and, to a much 

lesser extent, meadow. Losses would occur through vegetation clearing, grading, site development or 

other surface disturbance (e.g., driving over vegetation). As shown in table 9-33 below, only a small 

percentage of these vegetation communities would be affected by the facility actions at Curry Village. 

Impacts to meadow habitat would occur in a small meadow area currently disconnected from the larger 

Stoneman Meadow to the north by Happy Isle Loop Road. In addition, vegetation communities at Curry 

Village are adjacent to already developed areas, and therefore currently experience high levels of 

visitation and human-related impacts such as vegetation trampling and soil compaction. Therefore, 

losses of vegetation communities, while long-term, would be local, adverse and minor. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-292 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

TABLE 9-33: VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR USE AND FACILITIES 

AT CURRY VILLAGE & CAMPGROUNDS – ALTERNATIVE 4 

Vegetation/Wetland Type Acres 

Percent of Vegetation/Wetland 

Type Affected in Segmenta

Segment 2 

Meadow 0.03 <0.1% 

Lower Montane Coniferous 6.35 <0.1% 

Redevelopmentb 1.97 N/A 

Wetland (Palustrine Emergent) 0.04 <0.1% 

Wetland (Riverine Intermittent) 0.02 <0.1% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 

Direct impacts to vegetation, including trampling or removal of rooted vegetation, would cause a 

reduction of the total numbers of plants and/or a reduction or loss of total area, diversity, vigor, 

structure, or function of vegetative habitat. Direct impacts could also include decrease plant vigor or 

health from reduced water availability or dust accumulation on photosynthetic surfaces. 

Vegetation that would be removed at Curry Village under Alternative 4 would not substantially 

fragment existing native vegetation communities, reduce species diversity, or substantially reduce the 

overall size or quality of native plant communities in Yosemite Valley, as new construction would 

primarily occur in or adjacent to previously disturbed locations or in more resilient upland habitat. 

Wetlands would be avoided during construction activities. Adherence to proposed mitigation 

measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as applicable (see 

Appendix C), and avoidance of the removal of vegetation where possible, would reduce impacts to 

local, long-term, minor and adverse. 

Construction activities at Curry Village would result in direct, permanent losses of federally protected 

wetlands. Impacts to wetlands would occur in palustrine emergent wetlands associated with Stoneman 

Meadow and intermittent channels flowing through the area. Approximately 0.06 acres of potentially 

jurisdictional wetland features would be directly and permanently impacted by the proposed actions 

under Alternative 4. Losses to these wetlands would occur through site clearing, filling, grading, and 

subsequent development. Construction activities may also generate indirect impacts to wetlands 

including potential modifications to flow, circulation, hydroperiod, or other aspects of the hydrologic 

regime, and increases in sedimentation due to ground disturbance associated with construction. 

However, post-construction, temporarily impacted areas would be restored. Wetlands that cannot be 

avoided and would be permanently filled must be compensated to result in “no net loss” of wetlands. 

Adherence to proposed mitigation measures MM-HYD-1, MM-VEG-1, and MM-VEG-4 through 

MM-VEG-7, as applicable (see Appendix C), and avoidance of wetlands during construction where 

possible, would reduce impacts to wetlands to local, long-term, minor and adverse. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 4 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-293

Camp 6 and Yosemite Village. Actions under Alternative 4 in Segment 2 related to managing visitor use 

and facilities at Camp 6 and Yosemite Village include measures to formalize and relocate parking 

facilities 150 feet away from the river in order to facilitate riparian restoration goals. The Camp 6/Village 

Center Parking Area would be formalized to include 750 designated parking spaces by redeveloping part 

of the current administrative footprint. In addition, 100 parking spaces would be added at Yosemite 

Village. The intersection at Northside Drive and Village Drive (Camp 6 intersection) would be re-aligned 

to meet standards for a proper four-way intersection and improve performance. A three-way 

intersection at Sentinel Drive and the entrance to the parking area would be added to improve traffic 

flow and alleviate congestion. An entry road to Camp 6 parking lot from Sentinel Drive would be 

added to improve traffic flow and alleviate congestion at nearby intersections. On-grade pedestrian 

crossings with proper sight lines would be provided to alleviate pedestrian/vehicle conflicts. Expanded 

parking area and new road construction activities at Yosemite Village would result in direct temporary 

and permanent losses of native vegetation and wetlands as well as redevelopment of existing disturbed 

areas (see table 9-34). 

TABLE 9-34: VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR USE AND 

FACILITIES AT CAMP 6 AND YOSEMITE VILLAGE – ALTERNATIVE 4 

Vegetation/Wetland Type Acres 

Percent of 

Vegetation/Wetland Type 

Affected in Segmenta

Segment 2 

Meadow 0.28 <0.1% 

Lower Montane Coniferous 12.22 0.2% 

Lower Montane Broadleaf 0.81 <0.1% 

Redevelopmentb 14.18 N/A 

Wetland (Palustrine Emergent) 1.21 0.4% 

Wetland (Palustrine Forested) 0.96 0.8% 

Wetland (Riverine Intermittent) 0.39 0.3% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 

As noted in table 9-34, over half of the area affected by the above actions would occur at sites that are 

already developed. Outside of previously developed areas, impacts to vegetation would occur almost 

entirely in lower montane broadleaf forest and lower montane coniferous forest; these types are among 

the most dominant native vegetation communities in Segment 2. Impacts to meadow habitat would occur 

in an area currently impacted by its proximity to Sentinel Drive. Losses to these communities would 

occur through vegetation clearing, grading, site development or other surface disturbance (e.g., driving 

over vegetation). As shown in table 9-34, only a small percentage of these vegetation communities would 

be impacted by the actions at Camp 6 and Yosemite Village. In addition, potentially affected vegetation 

communities are adjacent to already developed areas, and therefore experience high levels of visitation 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-294 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

and human-related impacts such as vegetation trampling and soil compaction. Therefore, losses of 

vegetation communities, while long-term, would be local, adverse and minor. 

Vegetation that is removed at Yosemite Village under Alternative 4 would not substantially fragment 

existing native vegetation communities, reduce species diversity, or substantially reduce the overall 

size or quality of native plant communities in Yosemite Valley, as new construction would primarily 

occur in or adjacent to previously disturbed locations or in more resilient upland habitat. Adherence 

to proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, 

as applicable (see Appendix C), and avoidance of the removal of vegetation where possible, would 

reduce impacts to local, long-term, minor and adverse. 

Parking areas and new road construction activities at Camp 6 and Yosemite Village would result in 

direct, permanent losses of federally protected wetlands. Impacts to wetlands would occur in 

palustrine emergent wetlands located adjacent to the Northside Drive and Sentinel Crossover 

intersection, palustrine forested wetlands associated with the Merced River, and intermittent channels 

flowing through the area. Approximately 2.56 acres of potential jurisdictional wetland features would 

be directly and permanently impacted by the proposed actions under Alternative 4. Losses to these 

wetlands would occur through site clearing, filling, grading, and subsequent development. 

Construction activities may also generate indirect impacts to wetlands including potential 

modifications to flow, circulation, hydroperiod, or other aspects of the hydrologic regime, and 

increases in sedimentation due to ground disturbance associated with construction. However, postconstruction, temporarily impacted areas would be restored. Wetlands that cannot be avoided and 

would be permanently filled must be compensated to result in “no net loss” of wetlands. Adherence to 

proposed mitigation measures MM-HYD-1, MM-VEG-1, and MM-VEG-4 through MM-VEG-7, as 

applicable (see Appendix C), and avoidance of wetlands during construction where possible, would 

reduce impacts to wetlands to local, long-term, moderate and adverse. 

Yosemite Lodge and Camp 4. Actions under Alternative 4 in Segment 2 related to managing visitor 

use and facilities at Yosemite Lodge and Camp 4 include: the removal of old and temporary housing at 

Highland Court and the Thousands Cabins; the construction of two new concessioner housing areas 

and the construction of 78 employee parking spaces; redevelopment west of Yosemite Lodge to 

provide an additional 150 day use parking spaces and area for 15 tour buses; relocation of existing tour 

bus drop off area to Highland Court to provide 3 bus loading/unloading spaces; and the construction 

of a pedestrian underpass to alleviate pedestrian/vehicle conflicts. 

Like other proposed projects, construction activities at Yosemite Lodge would result in direct 

temporary and permanent losses of native vegetation and wetlands as well as the redevelopment of 

existing disturbed areas (see table 9-35). Impacts to vegetation would occur entirely in lower montane 

coniferous forest, the dominant natural vegetation community in Segment 2. Losses would occur 

through vegetation clearing, grading, site development or other surface disturbance (e.g., driving over 

vegetation). As shown in table 9-35, only a small percentage of this vegetation community would be 

impacted. In addition, potentially affected vegetation is adjacent to already developed areas, and 

therefore experience high levels of visitation and human-related impacts such as vegetation trampling 

and soil compaction. Therefore, losses of vegetation communities, while long-term, would be local, 

adverse and minor. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 4 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-295

TABLE 9-35: VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR USE AND 

FACILITIES AT YOSEMITE LODGE AND CAMP 4 – ALTERNATIVE 4 

Vegetation/Wetland Type Acres 

Percent of 

Vegetation/Wetland Type 

Affected in Segmenta

Segment 2 

Lower Montane Coniferous 14.80 0.2% 

Lower Montane Broadleaf 0.08 <0.1% 

Redevelopmentb 3.69 N/A 

Wetland (Riverine Intermittent) 0.03 <0.1% 

Wetland (Riverine Perennial) 0.02 <0.1% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 

Like other development actions proposed under this alternative, vegetation that is removed at Yosemite 

Lodge and Camp 4 under Alternative 4 would not substantially fragment existing native vegetation 

communities, reduce species diversity, or substantially reduce the overall size or quality of native plant 

communities in Yosemite Valley, as new construction would primarily occur in or adjacent to previously 

disturbed locations or in more resilient upland habitat. Wetlands would be avoided during construction 

activities. Adherence to proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 

through MM-VEG-7, as applicable (see Appendix C), and avoidance of the removal of vegetation 

where possible, would reduce impacts to local, long-term, minor and adverse. 

Construction activities at Yosemite Lodge and Camp 4 would result in direct, permanent losses of 

federally protected wetlands. Impacts to wetlands would occur along the Merced River and in 

intermittent channels flowing through the area. Approximately 0.05 acres of potentially jurisdictional 

wetland features would be directly and permanently impacted by the proposed actions under 

Alternative 4. Losses to these wetlands would occur through site clearing, filling, grading, and subsequent 

development. Construction activities may also generate indirect impacts to wetlands including potential 

modifications to flow, circulation, hydroperiod, or other aspects of the hydrologic regime, and increases 

in sedimentation due to ground disturbance associated with construction. However, post-construction, 

temporarily impacted areas would be restored. Wetlands that cannot be avoided and would be 

permanently filled must be compensated to result in “no net loss” of wetlands. Adherence to proposed 

mitigation measures MM-HYD-1, MM-VEG-1, and MM-VEG-4 through MM-VEG-7, as applicable 

(see Appendix C), and avoidance of wetlands during construction where possible, would reduce impacts 

to wetlands to local, long-term, minor and adverse. 

In summary, as shown in table 9-36, actions to manage visitor use and facilities would result in the loss 

of 34.57 acres of vegetation primarily located near previously developed areas, resulting in long-term, 

local, minor, adverse impacts to these communities. Actions to manage visitor use and facilities would 

result in the permanent loss of 2.67 acres of potentially jurisdictional wetlands. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-296 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

TABLE 9-36: SUMMARY OF VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR 

USE AND FACILITIES IN SEGMENT 2 – ALTERNATIVE 4 

Vegetation/Wetland Type Acres 

Percent of 

Vegetation/Wetland Type 

Affected in Segmenta

Segment 2 

Meadow 0.31 <0.1% 

Lower Montane Coniferous 33.37 0.5% 

Lower Montane Broadleaf 0.89 <0.1% 

Redevelopmentb 19.84 N/A 

Wetland 2.67 0.4%5 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 

Segment 2 Impact Summary: Actions to protect and enhance river values within Segment 2 under 

Alternative 4 would result in the restoration of 194 acres of vegetation and 44.52 acres of wetland, 

resulting in long-term, segmentwide, major, beneficial impacts on vegetation and wetlands. Actions to 

manage visitor use and facilities would result in the loss of 34.57 acres of vegetation primarily located 

near previously developed areas, resulting in long-term, local, minor to moderate, adverse impacts to 

these communities. Actions to manage visitor use and facilities would result in the permanent loss of 

2.67 acres of potentially jurisdictional wetlands. 

Segments 3 and 4: Merced Gorge and El Portal 

Impacts of Actions to Protect and Enhance River Values 

Currently, vehicles park under the dripline of the 38 valley oak trees. This practice compacts soil under 

the trees, affecting root health, water uptake, and soil aeration. Additionally, existing development and 

trampling in the vicinity limit the area where oak seedlings can be recruited. Under Alternative 4, valley 

oaks in El Portal would be enhanced by creating an oak recruitment area of one acre in Old El Portal in 

the vicinity of the current bulk fuel storage area, including the adjacent parking lots. Parking and new 

building construction within the oak recruitment area would be prohibited. Nonnative fill would be 

removed and soils decompacted. Appropriate native understory plant species would be planted. The 

fuel storage area would be relocated outside of the river corridor. Overall, these actions would result in 

local, long-term, moderate, beneficial impacts on valley oaks in El Portal. 

The types of habitat that would be affected by these restoration actions in Segment 4, as well as the 

types of habitat that would be enhanced or restored, are summarized in tables 9-37 and 9-38. A total 

of 12 acres of vegetation would be enhanced or restored in Segment 4, including 0.05 acres of wetlands 

(this includes restoration actions common to Alternatives 2-6). 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 4 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-297

TABLE 9-37: SEGMENT 4 VEGETATION RESTORATION UNDER ALTERNATIVE 4a

Current Vegetation Acres 

Current 

Habitat Type Acres

Proposed Future 

Habitat Type 

Acres Restored 

or Enhanced 

Valley oak woodland alliance 1 Foothill broadleaf 

woodland 1 Valley oak woodland 1 

Sparsely vegetated riverine 

flat 2 Sparsely vegetated 2 Riparian & floodplain: 

cottonwood, willow, 

mix of upland 

deciduous & 

coniferous forest 

canyon live oak-(Ponderosa 11 

pine-incense cedar) forest 

superassociation 

9 Lower montane 

broadleaf 9 

Total 12 12 12 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 

TABLE 9-38: SEGMENT 4 WETLAND RESTORATION UNDER ALTERNATIVE 4 

Wetland Type Acres 

Segment 4 

Palustrine Emergent 0.001 

Palustrine Forested 0.05 

Total amount of wetlands restored 0.05 

SOURCE: NPS 2012c 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Under Alternative 4, day parking would be expanded by 200 parking spaces at the Abbieville site; this 

area would be used primarily for visitor access to Yosemite Valley. NPS employee housing would be 

added to Abbieville, El Portal Village Center, and Rancheria Flat; a total of 292 employee parking 

spaces would be added at these locations. While all new units would be built outside of the 100-year 

floodplain, they would fall within the Merced River corridor. This increase in capacity in El Portal is a 

function of the decrease in employee housing capacity in Yosemite Valley (Segment 2). The addition of 

employee housing and park facilities development would increase the total built environment within 

Segment 4. 

Relocation of facilities to other locations within the corridor could have long-term, negligible to 

moderate, adverse effects on vegetation, depending on site-specific conditions and project design. 

Local, minor to moderate, short-term, adverse effects could occur from construction and demolition 

of facilities along the Merced River. Vegetation that is removed under Alternatives 2–6 would not 

substantially fragment existing native vegetation communities, reduce species diversity, or 

substantially reduce the overall size or quality of native plant communities at El Portal, as new 

construction would primarily occur in or adjacent to previously disturbed locations or in more 

resilient, upland habitat. Wetlands would be avoided during construction activities. Adherence to 

proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as 

applicable (see Appendix C), and avoidance of the removal of vegetation where possible, would reduce 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-298 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

short-term impacts to minor and adverse. Overall, these actions would result in local, short-term, 

minor, adverse impacts on plant communities in El Portal. 

Segments 3 and 4 Impact Summary: Actions to protect and enhance river values within Segments 3 

and 4 would result in the restoration of 12 acres of vegetation and 0.05 acres of wetland, resulting in 

long-term, local, moderate, beneficial impacts on vegetation and wetlands. Actions to manage visitor 

use and facilities would result in short-term, local, minor, adverse impacts to vegetation and wetlands. 

Segments 5, 6, 7, and 8: South Fork Merced River 

Impacts of Actions to Protect and Enhance River Values 

The Wawona Golf Course would not be removed under Alternative 4, and therefore effects related to 

its continued operation would be the same as described for Alternative 1. Actions specifically targeted 

to protect culturally sensitive areas would also benefit vegetation and wetlands, including the 

relocation or removal of select campsites and stock campground sites that are within the 100-year 

floodplain or culturally sensitive areas. The removal of select campsites within the floodplain would 

result in a local, long-term, minor, beneficial impact on riparian vegetation. 

The types of habitat that would be affected by these restoration actions in Segment 7, as well as the 

types of habitat that would be enhanced or restored, are summarized in table 9-39. A total of seven 

acres of vegetation would be restored in Segment 7 (this includes restoration actions common to 

Alternatives 2-6). 

TABLE 9-39: SEGMENT 7 VEGETATION RESTORATION UNDER ALTERNATIVE 4a

Current Vegetation Acres 

Current 

Habitat Type Acres

Proposed Future 

Habitat Type 

Acres Restored 

or Enhanced 

Ponderosa pine woodland 

alliance 1 

Lower montane 

needleleaf 7 

Riparian: cottonwood, 

willow, mix of upland 

deciduous & 

coniferous forest 

7 

Ponderosa pine-incense cedar 

forest alliance 5 

Ponderosa pine-incense cedar-

(California black oak-canyon 

live oak) forest superassociation 

1 

Total 7 7 7 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 

Biological Resource Actions. Specific projects to protect and enhance the river’s biological values 

that would occur within Segment 7 under Alternative 4 include the relocation of stock use campsites 

from sensitive resource areas to Wawona Stables. Overall, this action would result in a local, long-term, 

minor, beneficial impact on plant communities and wetlands in Wawona. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 4 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-299

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Under Alternative 4, the operations of the Wawona stables would be eliminated and two stock campsites 

would be relocated to this area from the current Wawona stock camp. The area would be restored. Soils 

would be decompacted and the area would be replanted with riparian vegetation. This would reduce 

visitor use in this area, resulting in a decrease of vegetation trampling. Overall, these actions would result 

in a local, long-term, minor, beneficial impact on plant communities and wetlands in Wawona. 

Wawona Campground. Facilities actions at the Wawona Campground would involve removal of 27 

sites that are either within the 100-year floodplain or in culturally sensitive areas. Overall, these actions 

would result in a local, long-term, minor, beneficial impact on plant communities and wetlands in 

Wawona. 

Segments 5, 6, 7 and 8 Impact Summary: Actions to protect and enhance river values within 

Segments 5, 6, 7 and 8 under Alternative 3 would result in the restoration of seven acres of vegetation, 

resulting in long-term, segmentwide, minor, beneficial impacts on vegetation and wetlands. Actions to 

manage visitor use and facilities would result in long-term, local, minor, beneficial impacts to 

vegetation and wetlands. 

Summary of Impacts from Alternative 4: Resource-based Visitor Experiences and Targeted 

Riverbank Restoration 

Alternative 4 would restore approximately 223 acres of vegetation, including 44.57 acres of wetlands, as a 

result of actions common to Alternatives 2-6 and those specific to Alternative 4. Actions to manage 

visitor use and facilities would result in the loss of approximately 34.57 acres of vegetation and the 

permanent loss of 2.67 acres of potentially jurisdictional wetlands as a result of actions specific to 

Alternative 4. 

Past development and human activity in the Merced River corridor have in some cases adversely 

affected vegetation communities and regional vegetation patterns. Actions associated with Alternative 

4 are expected to have corridorwide, long-term, moderate, beneficial impacts on vegetation in the 

Merced River corridor. Restoration actions associated with Alternative 4 would restore meadow and 

riparian areas, improve and restore hydrologic function and restore ecological integrity throughout 

the corridor, remove and restore informal trails, and direct the public onto established trails and river 

access points. This is part of a comprehensive strategy to reduce existing adverse impacts on meadow, 

wetland, and riparian vegetation. Existing natural resource management actions, such as removal of 

nonnative invasive plants, would continue. Adverse effects from these actions would be local, shortterm, and minor or negligible. There would be local, long-term, moderate, adverse impacts on native 

vegetation communities from construction of some facilities. Notable actions the park would 

implement under Alternative 4 include 

 restricting recreational use of rivers and riverbanks to reduce riverbank erosion 

 removing, restoring, relocating, or repurposing park facilities to efficiently utilize park 

facilities and reduce the built environment within the park; some facilities would be built to 

accommodate visitors or employees 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-300 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

 managing total visitors to the park and visitor demands for day parking space, lodging, and 

camping space 

 removing facilities within 150 feet of the Merced River and restoring riverbanks, meadows, 

and riparian habitat 

 enhancing meadow, riparian, and river hydrologic function, complexity, and connectivity 

 improving the free flow, complexity, and water quality of the Merced River 

Generally, Alternative 4 is focused on intensive restoration of meadow, riparian, and riverbank 

habitats in Yosemite Valley (Segment 2); removing many facilities that are located within 150 feet of 

the river and are jeopardized by flood; repurposing park facilities to improve efficiency of use; adding 

additional campground facilities; and providing adequate lodging, camping, and parking space for 

visitors and employees. Adverse effects from these actions would be associated with the active 

construction or restoration phase, and would be local, short-term, and minor or negligible. However, 

there would be local, long-term, moderate, adverse impacts on vegetation communities from 

construction of some facilities. These effects would be most pronounced in areas of high human use, 

such as Yosemite Valley and Wawona (Segments 2 and 7). When combined, the long-term effect of all 

of these measures would be a corridorwide, moderate, beneficial impact on vegetation communities as 

habitats are restored and fragmentation and edge effects reduced. 

Cumulative Impacts from Alternative 4: Resource-based Visitor Experiences and Targeted 

Riverbank Restoration 

The past, present, and reasonably foreseeable plans and projects that could have a cumulative impact 

on vegetation resources are the same as those listed under the No Action Alternative. Alternative 4 

would result in segmentwide, long-term, minor to moderate, beneficial impacts on vegetation 

communities within the Merced River corridor. These actions are focused on restoring and improving 

aquatic, meadow, and riparian habitat quality within the Merced River corridor. The past, present, and 

future actions in the region would have varying effects on vegetation and wetlands, with some projects 

restoring or enhancing vegetation and wetlands, and many others resulting in the loss or decline of 

vegetation and wetlands. For projects that would result in the loss of wetland features regulated under 

section 404 of the CWA, losses would be typically compensated at a ratio of 1:1 (no net loss). 

Compensation typically occurs through creation or enhancement of wetlands either on-site or at a 

designated mitigation bank. However, even with these protections in place, wetlands may be lost over 

time through unregulated activities or negatively impacted through nonpoint source pollution, 

nonnative species, and changes in surface and subsurface hydrology over time. 

The actions under Alternative 4 would have long-term, beneficial effects on vegetation and wetlands, 

including vegetation-related ORVs, within the Merced River corridor. However, in relation to past, 

present, and reasonably foreseeable future actions throughout the Sierra Nevada and larger region 

(e.g., introduction and spread of nonnative species, direct displacement of vegetation by structures), 

the actions under Alternative 4 would have a minimal beneficial effect. Overall, cumulative actions on 

vegetation and wetlands would result in long-term, minor, adverse effects on regional vegetation 

patterns. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 5 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-301

Environmental Consequences of Alternative 5: Enhanced Visitor Experiences and 

Essential Riverbank Restoration 

Segment 1: Merced River above Nevada Fall 

Impacts of Actions to Protect and Enhance River Values 

Under Alternative 5, grazing in Merced Lake East Meadow would be managed as described for 

Alternatives 3. Beneficial effects to vegetation would be the same as described for Alternative 3. 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Several actions related to management of visitor use and facilities would have the potential to affect 

vegetation and wetlands in Segment1 under Alternative 5. Visitation within Segment 1 would not be 

expected to change appreciably under Alternative 5; wilderness access quotas would remain as under 

Alternative 1 (No Action) and modifications to overnight accommodations would be nominal. Under 

Alternative 5, the Merced Lake High Sierra Camp would remain in operation and continue to host 

overnight guests and through-hikers during the summer months. However, the camp’s 60 beds would be 

reduced to 42 (11 units). The park would not reduce the total number of designated campsites within the 

Merced River corridor’s wilderness. Designated camping at Moraine Dome and Little Yosemite Valley 

Backpackers Campground would continue with overnight quotas of 150 people per day in Little Yosemite 

Valley. The Merced Lake Backpackers Campground would remain. Overall, these actions would result in 

a local, long-term, negligible, beneficial impact on plant communities and wetlands in Segment 1. 

Merced Lake High Sierra Camp. The project-level actions in the Merced Lake High Sierra Camp area 

proposed under Alternative 5 involve retention of the Merced Lake High Sierra Camp, reducing the 

capacity to 42 beds, and replacing the flush toilets with composting toilets. These actions would result in 

a local, long-term, negligible, beneficial impact on plant communities and wetlands in Segment 1.by 

reducing impacts on vegetation communities from visitor use and presence of infrastructure. 

Segment 1 Impact Summary: Actions to manage visitor use and facilities within Segment 1 under 

Alternative 5 would have local, long-term, negligible, beneficial impacts on plant communities and 

wetlands in the river corridor. 

Segment 2: Yosemite Valley 

Impacts of Actions to Protect and Enhance River Values 

Projects proposed in Segment 2 under Alternative 5 to protect and enhance river values involve 

constructing a boardwalk for the Valley Loop Trail through sensitive wet meadow habitat in 

Slaughterhouse Meadow; restoration of 10.9 acres of riparian habitat at the former Yosemite Lodge 

units and cabins; and moving 780 feet of the Valley Loop Trail out of Bridalveil Meadow. Habitat 

restoration actions in Segment 2 under Alternative 5 are displayed in figures 9-29 through 9-32. The 

types of habitat that would be affected by these restoration actions in Segment 2, as well as the types of 

habitat that would be enhanced or restored, are summarized in tables 9-40 and 9-41. A total of 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-302 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

TABLE 9-40: SEGMENT 2 VEGETATION RESTORATION UNDER ALTERNATIVE 5a

Current Vegetation Acres 

Current 

Habitat Type Acres

Proposed Future 

Habitat Type 

Acres Restored 

or Enhanced 

Intermittently to seasonally 

flooded meadow 13 

Meadow 16 

Meadow 18 Semi-permanently to 

permanently flooded meadow 3 

Sparsely vegetated 

undifferentiated 2 Sparsely vegetated 2 

Black cottonwood temporarily 

flooded forest alliance 1 

Lower montane 

broadleaf 15 Lower montane broadleaf 15 California black oak forest alliance 6 

California black oak /(bracken 

fern) forest mapping unit 8 

Douglas-fir-(White fir-incense 

cedar-Pondera pine) forest 

mapping unit 

1 

Lower montane 

needleleaf 65 

A mosaic of meadow, 

black oak, and open 

canopy coniferous 

forest 

65 

Ponderosa pine woodland 

alliance 1 

Ponderosa pine-incense cedar 

forest alliance 20 

Ponderosa pine-incense 

cedar-(California black oakcanyon live oak) forest 

superassociation 

43 

Black cottonwood 

temporarily flooded forest 

alliance 

1 Lower montane 

broadleaf 1 

Riparian & floodplain: 

cottonwood, willow, 

mix of upland 

deciduous & 

coniferous forest 

44 

Ponderosa pine-incense cedar 

forest alliance 19 

Lower montane 

needleleaf 41 Ponderosa pine-incense 

cedar-(California black oakcanyon live oak) forest 

superassociation 

22 

Urban/Developed 2 Barren 2 

Urban/Developed 4 Barren 4 

Riparian: cottonwood, 

willow, mix of upland 

deciduous & 

coniferous forest 

40 

Ponderosa pine-incense cedar 

forest alliance 22 

Lower montane 

needleleaf 36 Ponderosa pine-incense 

cedar-(California black oakcanyon live oak) forest 

superassociation 

14 

Total 182 182 182 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 
North Pines

Campground

Royal Arch Creek

wahnee Bike Path

Stoneman

Bridge

Lower Pines

Campground

Stoneman

Meadow

Clark's

Bridge

Backpackers

Campground

Ahwahnee

Bridge

Sugar Pine

Bridge

p Trail

Ahwahnee Hotel

Historic Landmark

Staircase

Falls

Upper Pines

Campground

Housekeeping

Camp

Camp Curry Village

Stock

Bridge

Housekeeping

Camp Bridge

Sou hs t

di e Dr vi e

LeConte Memorial Lodge

Historic Landmark

Merced RIver

Northside Drive

de Drive

Ahwahnee

Meadow

North Dome

Washington

Column

Stables Area

Curry Village Impa

Existing Vegetation and 

Surfaced Area

Barren

Lower Montane Br

Lower Montane Ne

Meadow

Water

Retain Building

Campground

Recreational Segm

SOURCE: NPS, 1997, 2011, 2012
Bridge

Sentinel

Merced River

Lost Arrow Drive

Lost Arrow Drive

Village Drive

Housekeeping

Camp

Superintendent's

Bridge

Sentinel Boardwalk

Norths di e Drive

Northside Drive

Rangers' Club

Historic Landmark

Chapel

Yosemite Valley

T

Yosemite Village

Southside Drive

Oak Lane

Sentinel Crossover

Tecoya Road

Tenaya Way

Camp 6 Road

Cedar Lane

a C st

Cel fil Cf r uo t

Bou dl

er L

na

e

Ahwahnee Road

Meadow

Cook's

Meadow

Ahwahnee

Meadow

Sentinel

Yosemite Village Im

Existing Vegetation and I

Recreational Segm

Retain Building

Water

Meadow

Lower Montane Nee

Lower Montane Bro

Barren

Surfaced Area

SOURCE: NPS, 1997, 2011, 2012

0 0.125 0.25

Miles

Map Area

Segment

4

Segment

3

Segment

2 Segment

1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment
Camp 4

Historic Site

Yosemite Lodge

Sentinel

Beach

Leidig

Meadow

Swinging

Bridge

Yosemite Lodge Road

Nor ht s di e Dr vi e

Sou 

Wahhoga

Merced RIver

Sentinel Beach

Picnic Area

Swinging Bridge

Picnic Area

Lower Yosemite

Fall Picnic Area Yosemite Lodge & Camp 4 Impact Area

Existing Vegetation and Infrastructure

Surfaced Area

Barren

Lower Montane Broadleaf

Lower Montane Needleleaf

Meadow

Water

Retain Building

Campground

Recreational Segment Corridor Classification

Habitat Restoration Actions

River Access

Remove Building

Black Oak Restoration

Meadow Restoration

Riparian Restoration

Riparian and Floodplain Restoration

Road mitigation

Boardwalk

Remove informal trail

New fencing

No Action for riprap

Keep riprap and plant

Remove riprap and bioengineer

Remove riprap and revegetate

SOURCE: NPS, 1997, 2011, 2012
Cathedral Beac

Bridge

El Capitan

Pohono

Bridge

UV140

|ÿ41

Northside Drive

El

Capitan

Leaning

Tower

Cathedral

Rocks

Cathedral

Spires

Meadow

El Capitan

Meadow

Bridalveil

Slaughterhouse

Meadow

Trailhead

Pohono

) ) )

Merced River

Cathedral Beach

Picnic Area

Wawona Road

El Capitan Trail 

Yosemite Lodge & Camp 4 

Existing Vegetation and Infrastr

Recreational Segment Cor

Campground

Retain Building

Water

Meadow

Lower Montane Needlelea

Lower Montane Broadleaf

Barren

Surfaced Area

Map Area

Segment

4

Segment

3

Segment

2 Segment

1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment

SOURCE: NPS, 1997, 2011, 2012
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 5 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-307

TABLE 9-41: SEGMENT 2 WETLAND RESTORATION UNDER ALTERNATIVE 5 

Wetland Type Acres 

Segment 2 

Palustrine Emergent 16.93 

Palustrine Forested 22.30 

Palustrine Scrub Shrub 1.14 

Total amount of wetlands restored 40.37 

SOURCE: NPS 2012c 

182 acres of vegetation would be restored in Segment 2, including 40.37 acres of wetlands (this 

includes restoration actions common to Alternatives 2-6). 

These restoration management actions would improve the hydrologic function and restore the 

ecological integrity of plant communities and wetlands in the Merced River corridor in Segment 2, 

address ongoing and future impacts on park resources and infrastructure, and manage visitor use and 

development along the river corridor. Removing abandoned underground infrastructure, restoring 

informal trails, removing conifers from meadows, directing visitor use, removing riprap, and restoring 

free-flowing conditions along the river corridor would be part of a comprehensive strategy to reduce 

existing adverse impacts on meadow and riparian vegetation. Overall, these actions would result in a 

segmentwide, long-term, moderate, beneficial impact on plant communities and wetlands in Segment 2. 

Biological Resource Actions. 

Yosemite Valley Campgrounds: Specific restoration actions under Alternative 5 to enhance the 

river’s biological values in Segment 2 include removing all campsites within 100 feet of the bed and 

banks of the Merced River and restoring 6.5 acres of floodplain/riparian habitat, and designating river 

access at the North Pines Campground. Restoration of riparian habitat throughout Yosemite Valley 

would result in segmentwide, long-term, minor to moderate, beneficial impacts to vegetation and 

wetlands. 

El Capitan Meadow: In addition to actions common to Alternatives 2-6 and similar to Alternative 4, 

Alternative 5 would install restoration fencing along the northern perimeter of El Capitan Meadow to 

designate appropriate meadow access points along boardwalks and viewing platforms. Alternative 5 

would remove all informal trails in sensitive and frequently inundated areas and in areas that trails incise 

meadow and promote habitat fragmentation. Restoration of El Capitan Meadow and rerouting or 

removal of informal trails would result in local, long-term, minor to moderate, beneficial impacts on 

vegetation and wetlands from reduction of trampling from foot traffic that causes habitat fragmentation. 

Ahwahnee Meadow: Similar to Alternative 4, specific actions under Alternative 5 in Segment 2 to 

enhance the river’s biological values at the Ahwahnee Meadow include: removing fill in sections of 

trails that passes through meadow and wetland habitats and replace the trails with boardwalk. Unlike 

Alternatives 2 and 3, Northside Drive and the adjacent bike path would remain under Alternative 5. 

Hydrological connectivity between both sides of Northside Drive would be enhanced by increasing 

the number of culverts. Trail improvement and meadow restoration would result in local, long-term, 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-308 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

minor to moderate, beneficial impacts on vegetation and wetlands at the Ahwahnee Meadow as 

wetland fragmentation and vegetation trampling is reduced, and wetland connectivity to the river is 

enhanced. 

Stoneman Meadow: Specific actions in Alternative 5 to enhance the biological values of the Merced 

River include enhancing Stoneman Meadow by redesigning the Orchard Parking Lot to promote 

water flows and restore drainage from the cliff walls to the meadow. Improving hydrological 

connectivity between the Orchard Parking Lot cliff walls and Stoneman Meadow would result in local, 

long-term, minor, beneficial impacts on vegetation and wetlands. 

Former Upper and Lower Rivers Campgrounds: Specific actions to enhance biological values of the 

Merced River at the Former Upper and Lower Rivers Campgrounds under Alternative 5 include 

restoring 35.6 acres of riparian and floodplain habitat at Lower Rivers Campground. While this area is 

largely undeveloped, Alternative 5 would remove remaining asphalt, decompact soils of former roads 

and campsites and re-establish former river cut-off channels that have been filled within the 

restoration area. Large box culverts would be placed under the road to allow water flow, and the 

riparian zone at former Upper River would be fenced and closed to protect the riverbank from 

trampling associated with the addition of walk-in campgrounds. Restoration taking place in the 

Former Upper and Lower Rivers Campground area would result in local, long-term, minor, beneficial 

impacts on vegetation and wetlands. 

These restoration management actions would improve hydrologic function and restore ecological 

integrity of the Merced River corridor in Segment 2 and associated plant communities and wetlands, 

address ongoing and future impacts on park resources and infrastructure, and manage visitor use and 

development along the river corridor. These actions would be part of a comprehensive strategy to reduce 

existing adverse impacts on meadow and riparian vegetation. Overall, these actions would result in a 

segmentwide, long-term, moderate, beneficial impact on plant communities and wetlands in Segment 2. 

Hydrologic/Geologic Resource Actions. Specific projects to protect and enhance the river’s 

hydrologic and geologic values that would occur within Segment 2 under Alternative 5 include: 

relocating unimproved Camp 6 parking; removing the Sugar Pine Bridge; placing large wood and 

constructed logjams along the base of Stoneman Bridge; and improving trail connectivity and routing 

in the vicinity of the Ahwahnee Bridge. These actions would result in enhanced channel free flow, 

increased channel complexity, increased streambank stability, and restored riparian habitat 

segmentwide. Overall these measures would improve the free-flowing condition of the river and 

restore the ecological integrity of Yosemite Valley riparian habitats, resulting in segmentwide, longterm, moderate beneficial impacts on plant communities and wetlands in Segment 2. 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Actions to manage visitor use and facilities under Alternative 5, specifically those concerning vehicle 

access and overnight accommodations, would result in a 5% decrease in daily Yosemite Valley visitation, 

from approximately 20,900 under Alternative 1 to 19,900. Day use visitation would decrease by 14%. 

However, due largely to increases in lodging and campground facilities, overnight visitation would 

increase by about 16%). Under Alternative 5, there would be a net increase in Yosemite Valley lodging 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 5 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-309

units. This would largely result from the increase in units at Curry Village and removal of units from 

Housekeeping Camp. The park would increase the total number of campsites within the Valley. 

Relocation of facilities to other locations within the corridor could have long-term, negligible to 

moderate, adverse effects on vegetation, depending on site-specific conditions and project design. 

Local, minor to moderate, short-term, adverse effects could occur from construction and demolition 

of facilities along the Merced River. Vegetation that is removed under Alternative 5 would not 

substantially fragment existing native vegetation communities, reduce species diversity, or 

substantially reduce the overall size or quality of native plant communities at Yosemite Valley, as new 

construction would primarily occur in or adjacent to previously disturbed locations or in more 

resilient, upland habitat. Wetlands would be avoided during construction activities. Adherence to 

proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as 

applicable (see Appendix C), and avoidance of the removal of vegetation where possible, would reduce 

short-term impacts to minor and adverse. Overall, these actions would result in local, short-term, 

minor to moderate, adverse impacts on plant communities in Yosemite Valley. 

Former Upper River Campground Area. Construction of new walk-in campgrounds and picnic area 

in undeveloped areas at the former Upper River Campground would preclude the ecological 

restoration of the former riparian/wetland/California black oak complex in the area. Fencing along the 

riverbank would mitigate potential additional trampling damage to riparian areas. Construction 

activities at Upper River Campground would result in direct, temporary and permanent losses of 

native vegetation as well as the redevelopment of existing developed areas. Outside of previously 

developed areas, impacts to vegetation would occur in lower montane coniferous forest. Losses would 

occur through vegetation clearing, grading, site development or other surface disturbance (e.g., driving 

over vegetation).Losses of vegetation communities, while long-term, would be local, adverse and 

moderate. 

Curry Village & Campgrounds. Actions under Alternative 5 in Segment 2 related to managing visitor 

use and facilities at Curry Village include the reorganization of Curry Village including the 

construction of 98 hard-sided units. The units would be constructed within previously developed 

areas as well as within habitats adjacent to the existing Curry Village site. 

Construction activities at Curry Village would result in direct, temporary and permanent losses of native 

vegetation and wetlands (see table 9-42) as well as the redevelopment of existing developed areas. Outside 

of previously developed areas, impacts to vegetation would occur in lower montane coniferous forest and, 

to a much lesser extern, meadow. Losses would occur through vegetation clearing, grading, site 

development or other surface disturbance (e.g., driving over vegetation). As shown in table 9-42 below, 

only a small percentage of these vegetation communities would be affected by the facility actions at Curry 

Village. Impacts to meadow habitat would occur in a small meadow area currently disconnected from the 

larger Stoneman Meadow to the north by Happy Isle Loop Road. In addition, vegetation communities at 

Curry Village are adjacent to already developed areas, and therefore currently experience high levels of 

visitation and human-related impacts such as vegetation trampling and soil compaction. Therefore, losses 

of vegetation communities, while long-term, would be local, adverse and minor. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-310 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

TABLE 9-42: VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR USE AND 

FACILITIES AT CURRY VILLAGE & CAMPGROUNDS – ALTERNATIVE 5 

Vegetation/Wetland Type Acres 

Percent of Vegetation/Wetland 

Type Affected in Segment a

Segment 2 

Meadow 0.03 <0.1% 

Lower Montane Coniferous 6.35 <0.1% 

Redevelopmentb 1.97 N/A 

Wetland (Palustrine Emergent) 0.04 <0.1% 

Wetland (Riverine Intermittent) 0.02 <0.1% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 

Direct impacts to vegetation, including trampling or removal of rooted vegetation, would cause a 

reduction of total numbers of plants and/or a reduction or loss of total area, diversity, vigor, structure, 

or function of vegetative habitat. Direct impacts could also include decrease plant vigor or health from 

reduced water availability or dust accumulation on photosynthetic surfaces. 

Vegetation that is removed at Curry Village under Alternative 5 would not substantially fragment 

existing native vegetation communities, reduce species diversity, or substantially reduce the overall 

size or quality of native plant communities in Yosemite Valley, as new construction would primarily 

occur in or adjacent to previously disturbed locations or in more resilient upland habitat. Wetlands 

would be avoided during construction activities. Adherence to proposed mitigation measures MMGEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as applicable (see Appendix C), and 

avoidance of the removal of vegetation where possible, would reduce impacts to local, long-term, 

minor and adverse. 

Construction activities at Curry Village would result in direct, permanent losses of federally protected 

wetlands. Impacts to wetlands would occur in palustrine emergent wetlands associated with Stoneman 

Meadow and intermittent channels flowing through the area. Approximately 0.06 acres of potentially 

jurisdictional wetland features would be directly and permanently impacted by the proposed actions 

under Alternative 5. Losses to these wetlands would occur through site clearing, filling, grading, and 

subsequent development. Construction activities may also generate indirect impacts to wetlands 

including potential modifications to flow, circulation, hydroperiod, or other aspects of the hydrologic 

regime, and increases in sedimentation due to ground disturbance associated with construction. 

However, post-construction, temporarily impacted areas would be restored. Wetlands that cannot be 

avoided and would be permanently filled must be compensated to result in “no net loss” of wetlands. 

Adherence to proposed mitigation measures MM-HYD-1, MM-VEG-1, and MM-VEG-4 through 

MM-VEG-7, as applicable (see Appendix C), and avoidance of wetlands during construction where 

possible, would reduce impacts to wetlands to local, long-term, minor and adverse. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 5 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-311

Camp 6 and Yosemite Village. Actions under Alternative 5 in Segment 2 related to managing visitor 

use and facilities at Camp 6 and Yosemite Village include measures to formalize and relocate parking 

facilities 150 feet away from the river in order to facilitate riparian restoration goals. The Camp 6/Village 

Center Parking Area would be formalized to include 850 designated parking spaces by redeveloping 

part of the current administrative footprint. In addition, 100 parking spaces would be added at 

Yosemite Village. Northside Drive would be re-routed to the south of the Yosemite Village day-use 

parking area. A pedestrian underpass and a roundabout at the Village Drive/Northside Drive (Camp 6) 

intersection would be constructed to address traffic congestion and pedestrian/vehicle conflicts. A 

three-way intersection at Sentinel Drive and the entrance to the parking area would be added to 

improve traffic flow and alleviate congestion at nearby intersections. Expanded parking area and new 

road construction activities at Yosemite Village would result in direct temporary and permanent losses 

of native vegetation and wetlands as well as the redevelopment of existing disturbed areas (see 

table 9-43). 

TABLE 9-43: VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR USE AND 

FACILITIES AT CAMP 6 AND YOSEMITE VILLAGE – ALTERNATIVE 5 

Vegetation/Wetland Type Acres 

Percent of 

Vegetation/Wetland Type 

Affected in Segmenta

Segment 2 

Meadow 0.28 <0.1% 

Lower Montane Coniferous 12.22 0.2% 

Lower Montane Broadleaf 0.81 <0.1% 

Redevelopmentb 14.18 N/A 

Wetland (Palustrine Emergent) 1.21 0.4% 

Wetland (Palustrine Forested) 0.96 0.8% 

Wetland (Riverine Intermittent) 0.39 0.3% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 

As noted in table 9-43, over half of the area affected by the above actions would occur at sites that are 

already developed. Outside of previously developed areas, impacts to vegetation would occur almost 

entirely in lower montane broadleaf forest and lower montane coniferous forest; these types are 

among the most dominant native vegetation communities in Segment 2. Impacts to meadow habitat 

would occur in an area currently impacted by its proximity to Sentinel Drive. Losses to these 

communities would occur through vegetation clearing, grading, site development or other surface 

disturbance (e.g., driving over vegetation). As shown in table 9-43, only a small percentage of these 

vegetation communities would be impacted by the actions at Camp 6 and Yosemite Village. In 

addition, potentially affected vegetation communities are adjacent to already developed areas, and 

therefore experience high levels of visitation and human-related impacts such as vegetation trampling 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-312 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

and soil compaction. Therefore, losses of vegetation communities, while long-term, would be local, 

adverse and minor. 

Vegetation that would be removed at Camp 6 and Yosemite Village under Alternative 5 would not 

substantially fragment existing native vegetation communities, reduce species diversity, or 

substantially reduce the overall size or quality of native plant communities in Yosemite Valley, as new 

construction would primarily occur in or adjacent to previously disturbed locations or in more 

resilient upland habitat. Adherence to proposed mitigation measures MM-GEO-1, MM-HYD-1, and 

MM-VEG-1 through MM-VEG-7, as applicable (see Appendix C), and avoidance of the removal of 

vegetation where possible, would reduce impacts to local, long-term, minor and adverse. 

Parking areas and new road construction activities at Camp 6 and Yosemite Village would result in 

direct, permanent losses of federally protected wetlands. Impacts to wetlands would occur in 

palustrine emergent wetlands located adjacent to the Northside Drive and Sentinel Crossover 

intersection, palustrine forested wetlands associated with the Merced River, and intermittent channels 

flowing through the area. Approximately 2.56 acres of potential jurisdictional wetland features would 

be directly and permanently impacted by the proposed actions under Alternative 5. Losses to these 

wetlands would occur through site clearing, filling, grading, and subsequent development. 

Construction activities may also generate indirect impacts to wetlands including potential 

modifications to flow, circulation, hydroperiod, or other aspects of the hydrologic regime, and 

increases in sedimentation due to ground disturbance associated with construction. However, postconstruction, temporarily impacted areas would be restored. Wetlands that cannot be avoided and 

would be permanently filled must be compensated to result in “no net loss” of wetlands. Adherence to 

proposed mitigation measures MM-HYD-1, MM-VEG-1, and MM-VEG-4 through MM-VEG-7, as 

applicable (see Appendix C), and avoidance of wetlands during construction where possible, would 

reduce impacts to wetlands to local, long-term, moderate and adverse. 

Yosemite Lodge and Camp 4. Actions under Alternative 5 in Segment 2 related to managing visitor 

use and facilities at Yosemite Lodge and Camp 4 include: the removal of old and temporary housing at 

Highland Court and the Thousands Cabins; the construction of two new concessioner housing areas 

and the construction of 78 employee parking spaces; redevelopment west of Yosemite Lodge to 

provide an additional 300 day use parking spaces and area for 15 tour buses; relocation of existing tour 

bus drop off area to Highland Court to provide 3 bus loading/unloading spaces; and the construction 

of a pedestrian underpass to alleviate pedestrian/vehicle conflicts. 

Like other proposed projects, construction activities at Yosemite Lodge would result in direct 

temporary and permanent losses of native vegetation and wetlands as well as the redevelopment of 

existing disturbed areas (see table 9-44). Impacts to vegetation would occur in lower montane 

coniferous forest, the dominant natural vegetation community in Segment 2, and to a much lesser 

extent in lower montane broadleaf forest. Losses would occur through vegetation clearing, grading, 

site development or other surface disturbance (e.g., driving over vegetation). As shown in table 9-44, 

only a small percentage of these vegetation communities would be impacted. In addition, potentially 

affected vegetation is adjacent to already developed areas, and therefore experience high levels of 

visitation and human-related impacts such as vegetation trampling and soil compaction. Therefore, 

losses of vegetation communities, while long-term, would be local, adverse and minor. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 5 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-313

TABLE 9-44: VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR USE AND 

FACILITIES AT YOSEMITE LODGE AND CAMP 4 – ALTERNATIVE 5 

Vegetation/Wetland Type Acres 

Percent of 

Vegetation/Wetland Type 

Affected in Segmenta

Segment 2 

Lower Montane Coniferous 15.47 0.2% 

Lower Montane Broadleaf 1.73 <0.1% 

Redevelopmentb 3.69 N/A 

Wetland (Palustrine Emergent) 0.01 <0.1% 

Wetland (Riverine Intermittent) 0.03 <0.1% 

Wetland (Riverine Perennial) 0.01 <0.1% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 

Like other development actions proposed under this alternative, vegetation that would be removed at 

Yosemite Lodge under Alternative 5 would not substantially fragment existing native vegetation 

communities, reduce species diversity, or substantially reduce the overall size or quality of native plant 

communities in Yosemite Valley, as new construction would primarily occur in or adjacent to previously 

disturbed locations or in more resilient upland habitat. Wetlands would be avoided during construction 

activities. Adherence to proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 

through MM-VEG-7, as applicable (see Appendix C), and avoidance of the removal of vegetation 

where possible, would reduce impacts to local, long-term, minor and adverse. 

Construction activities at Yosemite Lodge and Camp 4 would result in direct, permanent losses of 

federally protected wetlands. Impacts to wetlands would occur in palustrine emergent wetlands and 

along the Merced River and in intermittent channels flowing through the area. Approximately 0.05 acres 

of potentially jurisdictional wetland features would be directly and permanently impacted by the 

proposed actions under Alternative 5. Losses to these wetlands would occur through site clearing, filling, 

grading, and subsequent development. Construction activities may also generate indirect impacts to 

wetlands including potential modifications to flow, circulation, hydroperiod, or other aspects of the 

hydrologic regime, and increases in sedimentation due to ground disturbance associated with 

construction. However, post-construction, temporarily impacted areas would be restored. Wetlands that 

cannot be avoided and would be permanently filled must be compensated to result in “no net loss” of 

wetlands. Adherence to proposed mitigation measures MM-HYD-1, MM-VEG-1, and MM-VEG-4 

through MM-VEG-7, as applicable (see Appendix C), and avoidance of wetlands during construction 

where possible, would reduce impacts to wetlands to local, long-term, minor and adverse. 

In summary, as shown in table 9-45, actions to manage visitor use and facilities would result in the loss 

of 36.89 acres of vegetation primarily located near previously developed areas, resulting in long-term, 

local, minor, adverse impacts to these communities. Actions to manage visitor use and facilities would 

result in the permanent loss of 2.67 acres of potentially jurisdictional wetlands. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-314 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

TABLE 9-45: SUMMARY OF VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR 

USE AND FACILITIES IN SEGMENT 2 – ALTERNATIVE 5 

Vegetation/Wetland Type Acres 

Percent of 

Vegetation/Wetland Type 

Affected in Segmenta

Segment 2 

Meadow 0.31 <0.1% 

Lower Montane Coniferous 34.04 0.5% 

Lower Montane Broadleaf 2.54 <0.1% 

Redevelopmentb 19.84 N/A 

Wetland 2.67 0.5% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 

Segment 2 Impact Summary: Actions to protect and enhance river values within Segment 2 under 

Alternative 5 would result in the restoration of 182 acres of vegetation and 40.37 acres of wetland, 

resulting in long-term, segmentwide, major, beneficial impacts on vegetation and wetlands. Actions to 

manage visitor use and facilities would result in the loss of 36.89 acres of vegetation primarily located 

near previously developed areas, resulting in long-term, local, minor to moderate, adverse impacts to 

these communities. Actions to manage visitor use and facilities would result in the permanent loss of 

2.67 acres of potentially jurisdictional wetlands. 

Segments 3 and 4: Merced Gorge and El Portal 

Impacts of Actions to Protect and Enhance River Values 

Currently, vehicles park under the dripline of the 38 valley oak trees. This practice compacts soil under the 

trees, affecting root health, water uptake, and soil aeration. Additionally, existing development and 

trampling in the vicinity limits the area where oak seedlings can be recruited. Under Alternative 5, valley 

oaks in El Portal would be enhanced by creating an oak recruitment area of one acre in Old El Portal in the 

vicinity of the current bulk fuel storage area, including the adjacent parking lots. Parking and new building 

construction within the oak recruitment area would be prohibited. Nonnative fill would be removed and 

soils decompacted. Appropriate native understory plant species would be planted. The fuel storage area 

would be relocated outside of the river corridor. Overall, these actions would result in local, long-term, 

moderate, beneficial impacts on valley oaks in El Portal. 

The types of habitat that would be affected by these restoration actions in Segment 4, as well as the 

types of habitat that would be enhanced or restored, are summarized in tables 9-46 and 9-47. A total 

of 12 acres of vegetation would be enhanced or restored in Segment 4, including 0.05 acre of wetland 

(this includes restoration actions common to Alternatives 2-6). 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 5 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-315

TABLE 9-46: SEGMENT 4 VEGETATION RESTORATION UNDER ALTERNATIVE 5a

Current Vegetation Acres 

Current 

Habitat Type Acres

Proposed Future 

Habitat Type 

Acres Restored 

or Enhanced 

Valley oak woodland alliance 1 Foothill broadleaf 

woodland 1 Valley oak woodland 1 

canyon live oak-(Ponderosa 

pine-incense cedar) forest 

superassociation 

11 Lower montane 

broadleaf 11 Riparian & floodplain 11 

Total 12 12 12 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 

TABLE 9-47: SEGMENT 4 WETLAND RESTORATION UNDER ALTERNATIVE 5 

Wetland Type Acres 

Segment 4 

Palustrine Emergent 0.001 

Palustrine Forested 0.05 

Total amount of wetlands restored 0.05 

SOURCE: NPS 2012c 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Under Alternative 5, day parking would be expanded by 200 parking spaces at the Abbieville site; this 

area would be used primarily for visitor access to Yosemite Valley. NPS employee housing would be 

added to Abbieville, El Portal Village Center, and Rancheria Flat; a total of 292 employee parking 

spaces would be added at these locations. While all new units would be built outside of the 100-year 

floodplain, they would fall within the river corridor. This increase in capacity in El Portal is a function 

of the decrease in employee housing capacity in the Valley (Segment 2). The addition of employee 

housing and park facilities development would increase the total built environment within Segment 4. 

Relocation of facilities to other locations within the corridor could have long-term, negligible to 

moderate, adverse effects on vegetation, depending on site-specific conditions and project design. 

Local, minor to moderate, short-term, adverse effects could occur from construction and demolition 

of facilities along the Merced River. Vegetation that is removed under Alternatives 2–6 would not 

substantially fragment existing native vegetation communities, reduce species diversity, or 

substantially reduce the overall size or quality of native plant communities at El Portal, as new 

construction would primarily occur in or adjacent to previously disturbed locations or in more 

resilient, upland habitat. Wetlands would be avoided during construction activities. Adherence to 

proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as 

applicable (see Appendix C), and avoidance of the removal of vegetation where possible, would reduce 

short-term impacts to minor and adverse. Overall, these actions would result in local, short-term, 

minor, adverse impacts on plant communities in El Portal. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-316 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Segments 3 and 4 Impact Summary: Actions to protect and enhance river values within Segments 3 

and 4 would result in the restoration of 12 acres of vegetation and 0.05 acres of wetland, resulting in 

long-term, local, moderate, beneficial impacts on vegetation and wetlands. Actions to manage visitor 

use and facilities would result in short-term, local, minor, adverse impacts to vegetation and wetlands. 

Segments 5, 6, 7, and 8: South Fork Merced River 

Impacts of Actions to Protect and Enhance River Values 

The Wawona Golf Course would not be removed under Alternative 5, and therefore effects related to 

its continued operation would be the same as described for Alternative 1. Actions specifically targeted 

to protect culturally sensitive areas would also benefit vegetation and wetlands, including the 

relocation or removal of select campsites and stock campground sites that are within the 100-year 

floodplain or culturally sensitive areas. The removal of select campsites within the floodplain would 

result in a local, long-term, minor, beneficial impact on riparian vegetation. 

The types of habitat that would be affected by these restoration actions in Segment 7, as well as the 

types of habitat that would be enhanced or restored, are summarized in table 9-48. A total of three 

acres of vegetation would be restored in Segment 7 (this includes restoration actions common to 

Alternatives 2-6). 

TABLE 9-48: SEGMENT 7 VEGETATION RESTORATION UNDER ALTERNATIVE 5a

Current Vegetation Acres 

Current 

Habitat Type Acres

Proposed Future 

Habitat Type 

Acres Restored 

or Enhanced 

Ponderosa pine woodland 

alliance 1 

Lower montane 

needleleaf 3 

Riparian: cottonwood, 

willow, mix of upland 

deciduous & 

coniferous forest 

3 

Ponderosa pine-incense cedar 

forest alliance 2 

Total 3 3 3 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 

Biological Resource Actions. Specific projects to protect and enhance the river’s biological values 

that would occur within Segment 7 under Alternative 5 include the relocation of stock use campsites 

from sensitive resource areas to the Wawona maintenance yard. Overall, this action would result in a 

local, long-term, minor, beneficial impact on plant communities and wetlands in Wawona. 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Under Alternative 5, the operations of the Wawona stables would be eliminated and two stock 

campsites would be relocated to this area from the current Wawona stock camp. Thirteen campsites in 

the Wawona Campground would be removed from within 100 feet of the Merced River or from 

cultural sites. The area would be restored. Soils would be decompacted and the area would be 

replanted with riparian vegetation. This would reduce visitor use in this area, resulting in a decrease of 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 5 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-317

vegetation trampling. Overall, these actions would result in a local, long-term, minor, beneficial impact 

on plant communities and wetlands in Wawona. 

Wawona Campground. Facilities actions at the Wawona Campground would involve removal of 13 

sites that are either within the 100-year floodplain or in culturally sensitive areas. Overall, these actions 

would result in a local, long-term, minor, beneficial impact on plant communities and wetlands in 

Wawona. 

Segments 5, 6, 7 and 8 Impact Summary: Actions to protect and enhance river values within 

Segments 5, 6, 7 and 8 under Alternative 5 would result in the restoration of three acres of vegetation, 

resulting in long-term, segmentwide, minor, beneficial impacts on vegetation and wetlands. Actions to 

manage visitor use and facilities would result in long-term, local, minor, beneficial impacts to 

vegetation and wetlands. 

Summary of Impacts from Alternative 5: Enhanced Visitor Experiences and Essential 

Riverbank Restoration 

Alternative 5 would restore approximately 197 acres of vegetation, including 40.52 acres of wetlands, 

as a result of actions common to Alternatives 2-6 in conjunction with actions specific to Alternative 5. 

Actions to manage visitor use and facilities would result in the loss of approximately 36.89 acres of 

vegetation and the permanent loss of 2.67 acres of potentially jurisdictional wetlands as a result of 

actions specific to Alternative 5. 

Past development and human activity in the Merced River corridor have in some cases adversely 

affected vegetation communities and regional vegetation patterns. Actions associated with Alternative 

5 are expected to have corridorwide, long-term, moderate, beneficial impacts on vegetation in the 

Merced River corridor. Restoration actions associated with Alternative 5 would restore meadow and 

riparian areas, improve and restore hydrologic function and restore ecological integrity throughout 

the corridor, remove and restore informal trails, and direct the public onto established trails and river 

access points. This is part of a comprehensive strategy to reduce existing adverse impacts on meadow, 

wetland, and riparian vegetation. Existing natural resource management actions, such as removal of 

nonnative invasive plants, would continue. Adverse effects from these actions would be local, shortterm, and minor or negligible. There would be local, long-term, moderate, adverse impacts on native 

vegetation communities from construction of some facilities. Notable actions the park would 

implement under Alternative 5 include 

 restricting recreational use of rivers and riverbanks to reduce riverbank erosion 

 removing, restoring, relocating, or repurposing park facilities to efficiently utilize park 

facilities and reduce the built environment within the park; some facilities would be built to 

accommodate visitors or employees 

 managing total visitors to the park and visitor demands for day parking space, lodging, and 

camping space 

 removing facilities within 100 feet of the Merced River and restoring riverbanks, meadows, 

and riparian habitat 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-318 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

 enhancing meadow, riparian, and river hydrologic function, complexity, and connectivity 

 improving the free flow, complexity, and water quality of the Merced River 

Generally, Alternative 5 focuses on intensive restoration of meadow, riparian, and riverbank habitats 

in Yosemite Valley (Segment 2) by removing many flood-prone facilities that are located within 

100 feet of the Merced River; repurposing park facilities to improve efficiency; maintaining existing 

use levels; and providing adequate lodging, camping, and parking space for visitors and employees. 

Adverse effects from these actions would be associated with active construction or ecological 

restoration, and would be local, short-term, and minor or negligible. However, there would be local, 

long-term, moderate, adverse impacts on vegetation communities from construction of some facilities. 

In addition, visitor use would remain consistent with current levels, and therefore vegetation would 

continue to be affected in some areas where use is intense (i.e., Curry Village, east Yosemite Valley). 

These effects would be most pronounced in areas of high human use, such as Yosemite Valley and 

Wawona (Segments 2 and 7).In total, the long-term effect of all of these measures would be a 

corridorwide, moderate, beneficial impact on vegetation communities as habitats are restored and 

habitat fragmentation is reduced. 

Cumulative Impacts from Alternative 5: Enhanced Visitor Experiences and Essential 

Riverbank Restoration 

The past, present, and reasonably foreseeable plans and projects that could have a cumulative impact 

on vegetation resources are the same as those listed under the No Action Alternative. Alternative 5 

would result in segmentwide, long-term, minor to moderate, beneficial impacts on vegetation 

communities within the Merced River corridor. These actions focused on restoring and improving 

aquatic, meadow, and riparian habitat quality within the Merced River corridor. The past, present, and 

future actions in the region would have varying effects on vegetation and wetlands, with some projects 

restoring or enhancing vegetation and wetlands, and many others resulting in the loss or decline of 

vegetation and wetlands. For projects that would result in the loss of wetland features regulated under 

section 404 of the CWA, losses would be typically compensated at a ratio of 1:1 (no net loss). 

Compensation typically occurs through creation or enhancement of wetlands either on-site or at a 

designated mitigation bank. However, even with these protections in place, wetlands may be lost over 

time through unregulated activities or negatively impacted through nonpoint source pollution, 

nonnative species, and changes in surface and subsurface hydrology over time. 

The actions under Alternative 5 would have long-term, beneficial effects on vegetation and wetlands, 

including vegetation-related ORVs, within the Merced River corridor. However, in relation to past, 

present, and reasonably foreseeable future actions throughout the Sierra Nevada and larger region 

(e.g., introduction and spread of nonnative species, direct displacement of vegetation by structures), 

the actions under Alternative 5 would have a minimal beneficial effect. Overall, cumulative actions on 

vegetation and wetlands would result in long-term, minor adverse effects on regional vegetation 

patterns. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 6 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-319

Environmental Consequences of Alternative 6: Diversified Visitor Experiences and 

Selective Riverbank Restoration 

Segment 1: Merced River above Nevada Fall 

Impacts of Actions to Protect and Enhance River Values 

Under Alternative 6, grazing in Merced Lake East Meadow would be managed as described for 

Alternatives 3. Beneficial effects to vegetation would be the same as described for Alternative 3. 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Several actions related to management of visitor use and facilities would have the potential to affect 

vegetation and wetlands in Segment 1 under Alternative 6. Visitation within Segment 1 would not be 

expected to change appreciably under Alternative 6; wilderness access quotas would remain as under 

Alternative 1 (No Action) and modifications to overnight accommodations would be nominal. Under 

Alternative 6, the Merced Lake High Sierra Camp would remain in operation and continue to host 

overnight guests and through-hikers during the summer months. The camp’s 60 beds (22 units) would 

remain. The park would not reduce the total number of designated campsites within the Merced River 

corridor’s wilderness. 

Total daily use levels for Segment 1 under Alternative 6 are estimated at 380 overnight visitors and 

approximately 450 day visitors, the same as Alternative 1 (No Action). Collectively, actions to maintain 

similar kinds and levels of use as current levels would result in continued local, long-term, minor, 

adverse impacts on vegetation and wetlands within Segment 1. 

Merced Lake High Sierra Camp. Actions in the Merced Lake High Sierra Camp area proposed under 

Alternative 6 involve retention of the Merced Lake High Sierra Camp and replacing the flush toilets 

with composting toilets. Actions to maintain current kinds and levels of use would continue local, 

long-term, minor, adverse impacts on vegetation and wetlands within Segment 1 through the effects of 

concentrated human use. 

Segment 1 Impact Summary: Actions to manage visitor use and facilities within Segment 1 under 

Alternative 6 would have local, long-term, minor, adverse impacts on plant communities and wetlands 

in the river corridor. 

Segment 2: Yosemite Valley 

Impacts of Actions to Protect and Enhance River Values 

Projects proposed in Segment 2 under Alternative 6 to protect and enhance river values in addition to 

those proposed under actions common to Alternatives 2-6 would construct a boardwalk for the Valley 

Loop Trail through sensitive wet meadow habitat in Slaughterhouse Meadow; and move 780 feet of 

the Valley Loop Trail out of Bridalveil Meadow. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-320 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Habitat restoration actions in Segment 2 under Alternative 6 are displayed in figures 9-33 through 

9-36. The types of habitat that would be affected by these restoration actions in Segment 2, as well as 

the types of habitat that would be enhanced or restored, are summarized in tables 9-49 and 9-50. A 

total of 156 acres of vegetation would be restored in Segment 2, including 37.32 acres of wetlands (this 

includes restoration actions common to Alternatives 2-6). 

These restoration management actions would improve the hydrologic function and restore the 

ecological integrity of plant communities and wetlands in the Merced River corridor in Segment 2, 

address ongoing and future impacts on park resources and infrastructure, and manage visitor use and 

development along the river corridor. Removing abandoned underground infrastructure, restoring 

informal trails, removing conifers from meadows, directing visitor use, removing riprap, and restoring 

free-flowing conditions along the river corridor would be part of a comprehensive strategy to reduce 

existing adverse impacts on meadow and riparian vegetation. Overall, these actions would result in a 

segmentwide, long-term, moderate, beneficial impact on plant communities and wetlands in Segment 2. 

Biological Resource Actions. 

Yosemite Valley Campgrounds: Like Alternative 5, specific restoration actions under Alternative 6 to 

enhance the river’s biological values in Segment 2 include removing all campsites within 100 feet of the 

bed and banks of the Merced River and restoring 6.5 acres of floodplain/riparian habitat, and 

designating river access at the North Pines Campground. Restoration of riparian habitat throughout 

Yosemite Valley would result in segmentwide, long-term, minor to moderate, beneficial impacts to 

vegetation and wetlands. 

El Capitan Meadow: Alternative 6 would install restoration fencing along the northern perimeter of 

El Capitan Meadow to designate appropriate meadow access points along boardwalks and viewing 

platforms. The NPS would remove all informal trails in sensitive and frequently inundated areas and in 

areas that trails incise meadow and promote habitat fragmentation. Additionally, Alternative 6 would 

selectively remove conifers that block the views of El Capitan from the roadside. Restoration of 

El Capitan Meadow and rerouting or removal of informal trails would result in local, long-term, minor 

to moderate, beneficial impacts on vegetation and wetlands from reduction of trampling from foot 

traffic that causes habitat fragmentation. 

Ahwahnee Meadow: Similar to Alternatives 4 and 5, specific actions under Alternative 6 in Segment 2 

to enhance the river’s biological values at the Ahwahnee Meadow include: removing fill in sections of 

trails that passes through meadow and wetland habitats and replace the trails with boardwalk. Unlike 

Alternatives 2 and 3, Northside Drive and the bike path adjacent to Ahwahnee Meadow would remain 

under Alternative 6. Hydrological connectivity between both sides of Northside Drive would be 

enhanced by increasing the number of culverts. Trail improvement and meadow restoration would 

result in local, long-term, minor to moderate, beneficial impacts on vegetation and wetlands at the 

Ahwahnee Meadow as wetland fragmentation and vegetation trampling is reduced, and wetland 

connectivity to the river is enhanced. 

Stoneman Meadow: Like Alternative 5, specific actions in Alternative 6 to enhance the biological 

values of the Merced River include restoring Stoneman Meadow by redesigning the Orchard Parking 

Lot. Through engineering solutions, Alternative 6 would promote water flow by increasing drainage 
N or th Pines

C ampgr o und

R

Stoneman

Bridge

L ower Pines

C ampground

Stoneman

M eadow

C lark's

Bridge

B ackpackers

C ampground

Ahwahnee

Bridge

Sugar Pine

Bridge

Ahwahnee H otel

H istoric L andmark

H appy

Isles Bridge

H appy Isles

Nature C enter

se

U pper Pines

C ampgr o und

H ousekeeping

C amp

C amp C urry V illage

Stock

Bridge

H ousekeeping

C amp Bridge

H appy

Isles Fen

Sou hs t di e Dr vi e

L eC onte M emorial L odge

H istoric L andmark

M erced R I ver

U pper and L ower

R iver C ampground A rea

N orthside D rive

Stables A rea

0 0.125 0.25

Miles

Existing Vegetation and Infrastructure

Surfaced AreaBarrenLower Montane BroadleafLower Montane NeedleleafMeadowWaterRetain BuildingCampgroundRecreational Segment Corridor Classification

Habitat Restoration Actions

Dump Station RemovalRiver AccessRemove BuildingMeadow RestorationRiparian RestorationRiparian and Floodplain Restoration

BoardwalkRemove informal trailBrush layerFill ditchFill removalNew fencingRemove pipeKeep riprap and plantRemove riprap and bioengineerRemove riprap and revegetateRoad removal; Trail removalRevegetate

Merced River Comprehensive Management Plan and EIS . 210436

Figure 9-33

Curry Village Area: Alternative 6 Habitat Restoration Actions

and Select Facilities Actions

SOURCE: NPS, 1997, 2011, 2012

Map Area

Segment

4

Segment

3

Segment

2 Segment 1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment

Curry Village Impact Area
Bridge

Sentinel

Merced R iver

R oyal Arch C reek

BridgeStoneman

C ampground

L ower Pines

M eadow

Stoneman

L ost A rrow Drive

L ost A rrow D rive

Ahwahnee

Bridge

Arch C ascadeR oyal

Village Drive

H ousekeeping

C amp

Superintendent's

Bridge

C amp BridgeH ousekeeping

walk

N orths di e D rive

N

orthside

Drive

R angers' C lub

H istoric L andmark

C hapelYosemite Valley

T he A hwahnee H otel

H istoric L andmark

Yo sem ite V i llage

U pper and L ower

R iver C ampground Area

N orthside D rive

Southside D rive

Oak L ane

Sentinel C rossover

Tecoya R oad

Tenaya W

ay

C amp 6 R oad

C edar L ane

a C st el il C Cff r uo t

Bou dl er L na e

Ahwahnee R oad

C ook's

M eadow

M eadow

Ahwahnee

M eadow

Sentinel

Existing Vegetation and Infrastructure

Recreational Segment Corridor ClassificationRetain BuildingCampgroundWaterMeadowLower Montane NeedleleafLower Montane BroadleafBarrenSurfaced Area

Habitat Restoration Actions

Remove informal trailBoardwalkRoad mitigation

Riparian and Floodplain RestorationRiparian RestorationMeadow RestorationBlack Oak RestorationRemove BuildingRiver Access

RevegetateRoad removal; Trail removalRemove riprap and revegetateRemove riprap and bioengineerKeep riprap and plantNo Action for riprapNew fencingFill removalFill ditchBrush layer

Merced River Comprehensive Management Plan and EIS . 210436

Figure 9-34

Yosemite Village Area: Alternative 6 Habitat Restoration Actions

and Select Facilities Actions

SOURCE: NPS, 1997, 2011, 2012

0 0.125 0.25

Miles

Map Area

Segment

4

Segment

3

Segment

2 Segment

1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment

Camp 6 & Yosemite Village Impact Area
Camp 4

Historic Site

Yosemite Lodge

Sentinel

Beach

Leidig

Meadow

Swinging

Bridge

Yosemite Lodge Road

Nor ht s di e Dr vi e

Sou 

Wahhoga

Merced RIver

Sentinel Beach

Picnic Area

Swinging Bridge

Picnic Area

Lower Yosemite

Fall Picnic Area Yosemite Lodge & Camp 4 Impact Area

Existing Vegetation and Infrastructure

Surfaced Area

Barren

Lower Montane Broadleaf

Lower Montane Needleleaf

Meadow

Water

Retain Building

Campground

Recreational Segment Corridor Classification

Habitat Restoration Actions

River Access

Remove Building

Black Oak Restoration

Meadow Restoration

Riparian Restoration

Riparian and Floodplain Restoration

Road mitigation

Boardwalk

Remove informal trail

New fencing

No Action for riprap

Keep riprap and plant

Remove riprap and bioengineer

Remove riprap and revegetate

SOURCE: NPS, 1997, 2011, 2012
Cathedral Beac

Bridge

El Capitan

Pohono

Bridge

UV140

|ÿ41

Northside Drive

El

Capitan

Leaning

Tower

Cathedral

Rocks

Cathedral

Spires

Meadow

El Capitan

Meadow

Bridalveil

Slaughterhouse

Meadow

Trailhead

Pohono

) ) )

Merced River

Cathedral Beach

Picnic Area

Wawona Road

El Capitan Trail 

Yosemite Lodge & Camp 4 

Existing Vegetation and Infrastr

Recreational Segment Cor

Campground

Retain Building

Water

Meadow

Lower Montane Needlelea

Lower Montane Broadleaf

Barren

Surfaced Area

Map Area

Segment

4

Segment

3

Segment

2 Segment

1

Segment

5

Segments

6,7

Segment

8

Recreational Segment Scenic Segment Wild Segment

SOURCE: NPS, 1997, 2011, 2012
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 6 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-325

TABLE 9-49: SEGMENT 2 VEGETATION RESTORATION UNDER ALTERNATIVE 6a

Current Vegetation Acres 

Current 

Habitat Type Acres

Proposed Future 

Habitat Type 

Acres Restored 

or Enhanced 

Intermittently to seasonally 

flooded meadow 12 

Meadow 16 

Meadow 18 Semi-permanently to permanently 

flooded meadow 3 

Sparsely vegetated 

undifferentiated 2 Sparsely vegetated 2 

Black cottonwood temporarily 

flooded forest alliance 1 

Lower montane 

broadleaf 15 Lower montane broadleaf 15 California black oak forest 

alliance 6 

California black oak /(bracken 

fern) forest mapping unit 8 

Douglas-fir-(White fir-incense 

cedar-Pondera pine) forest 

mapping unit 

1 

Lower montane 

needleleaf 58 

A mosaic of meadow, 

black oak, and open 

canopy coniferous 

forest 

58 Ponderosa pine-incense cedar 

forest alliance 18 

Ponderosa pine-incense cedar-

(California black oak-canyon live 

oak) forest superassociation 

39 

Black cottonwood temporarily 

flooded forest alliance 1 Lower montane broadleaf 1 

Riparian & floodplain: 

cottonwood, willow, 

mix of upland 

deciduous & 

coniferous forest 

29 

Ponderosa pine-incense cedar 

forest alliance 11 

Lower montane 

needleleaf Ponderosa pine-incense cedar- 28 

(California black oak-canyon live 

oak) forest superassociation 

17 

Urban/Developed 4 Barren 4 

Riparian: cottonwood, 

willow, mix of upland 

deciduous & 

coniferous forest 

36 

Ponderosa pine-incense cedar 

forest alliance 20 

Lower montane 

needleleaf Ponderosa pine-incense cedar- 32 

(California black oak-canyon live 

oak) forest superassociation 

12 

Total 156 156 156 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 

TABLE 9-50: SEGMENT 2 WETLAND RESTORATION UNDER ALTERNATIVE 6 

Wetland Type Acres 

Segment 2 

Palustrine Emergent 17.13 

Palustrine Forested 19.46 

Palustrine Scrub Shrub 0.73 

Total amount of wetlands restored 37.32 

SOURCE: NPS 2012c 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-326 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

from the cliff walls of the parking lot to Stoneman Meadows, thus improving meadow heath. 

Improving hydrological connectivity between the Orchard Parking Lot cliff walls and Stoneman 

Meadow would result in local, long-term, minor, beneficial impacts on vegetation and wetlands. 

Former Upper and Lower Rivers Campgrounds: Like Alternative 5, specific actions to enhance 

biological values of the Merced River at the Former Upper and Lower Rivers Campgrounds under 

Alternative 6 include restoring the topography of 16.5 acres of the floodplain within 150 feet of the 

ordinary high-water mark of the Merced River. While this area is largely undeveloped, Alternative 6 

would remove remaining asphalt; decompact soils in former roadbeds and campsites; re-establish 

former river cut-off channels and remove imported fill; and place large box culverts under the road to 

allow water flow. To protect the riverbank from trampling associate with the addition of walk-in 

campgrounds, the riparian zone at the former Upper River Campground site would be fenced and 

closed. Restoration of the riverside area at Former Upper and Lower Rivers Campgrounds would 

result in local, long-term, minor, beneficial impacts on vegetation and wetlands. 

These restoration management actions would improve hydrologic function and restore ecological 

integrity of the Merced River corridor in Segment 2 and associated plant communities and wetlands, 

address ongoing and future impacts on park resources and infrastructure, and manage visitor use and 

development along the river corridor. These actions would be part of a comprehensive strategy to reduce 

existing adverse impacts on meadow and riparian vegetation. Overall, these actions would result in a 

segmentwide, long-term, moderate, beneficial impact on plant communities and wetlands in Segment 2. 

Hydrologic/Geologic Resource Actions. Specific projects to protect and enhance the river’s 

hydrologic and geologic values that would occur within Segment 2 under Alternative 6 include 

relocating unimproved Camp 6 parking and placing large wood and constructed logjams along the 

bases of Stoneman, Sugar Pine, and Ahwahnee Bridges. These actions would result in enhanced 

channel free flow, increased channel complexity, increased streambank stability, and restored riparian 

habitat segmentwide. Overall these measures would improve the free-flowing condition of the river 

and restore the ecological integrity of Yosemite Valley riparian habitats, resulting in segmentwide, 

long-term, moderate beneficial impacts on plant communities and wetlands in Segment 2. 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Actions to manage visitor use and facilities under Alternative 6, specifically those concerning vehicle 

access and overnight accommodations, would result in a 4% increase in daily Yosemite Valley 

visitation, from approximately 20,900 under Alternative 1 to 21,800. Day use would decrease by 7%. 

However, due largely to increases in lodging and campground facilities, overnight visitation would 

increase by about 33%. Under Alternative 6, there would be a net increase in Yosemite Valley lodging 

units. This would largely result from the substantial increase in units at Yosemite Lodge and Curry 

Village, along with a slight reduction in Housekeeping Camp units. The park would increase the total 

number of campsites within the Valley. 

Relocation of facilities to other locations within the corridor could have long-term, negligible to 

moderate, adverse effects on vegetation, depending on site-specific conditions and project design. 

Local, minor to moderate, short-term, adverse effects could occur from construction and demolition 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 6 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-327

of facilities along the Merced River. Vegetation that is removed under Alternatives 2–6 would not 

substantially fragment existing native vegetation communities, reduce species diversity, or 

substantially reduce the overall size or quality of native plant communities in Yosemite Valley, as new 

construction would primarily occur in or adjacent to previously disturbed locations or in more 

resilient, upland habitat. Wetlands would be avoided during construction activities. Adherence to 

proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as 

applicable (see Appendix C), and avoidance of the removal of vegetation where possible, would reduce 

short-term impacts to minor and adverse. Overall, these actions would result in local, short-term, 

minor to moderate, adverse impacts on plant communities in Yosemite Valley. 

Former Upper and Lower River Campground Area. Construction of new walk-in campgrounds and 

picnic area in undeveloped areas at the former Upper and Lower Campgrounds would preclude the 

ecological restoration of the former riparian/wetland/California black oak complex in the area. 

Fencing along the riverbank would mitigate potential additional trampling damage to riparian areas. 

Construction activities at Upper and Lower River Campground would result in direct, temporary and 

permanent losses of native vegetation as well as the redevelopment of existing developed areas. 

Outside of previously developed areas, impacts to vegetation would occur in lower montane coniferous 

forest. Losses would occur through vegetation clearing, grading, site development or other surface 

disturbance (e.g., driving over vegetation). Losses of vegetation communities, while long-term, would 

be local, adverse and moderate. 

Curry Village & Campgrounds. Actions under Alternative 6 in Segment 2 related to managing visitor 

use and facilities at Curry Village include the reorganization of Curry Village including the 

construction of 98 hard-sided units. The units would be constructed within previously developed 

areas as well as within vegetation communities adjacent to the existing Curry Village site. 

Construction activities at Curry Village would result in direct, temporary and permanent losses of 

native vegetation and wetlands (see table 9-51) as well as the redevelopment of existing developed 

areas. Outside of previously developed areas, impacts to vegetation would occur in lower montane 

coniferous forest and, to a lesser extent, meadow. Losses would occur through vegetation clearing, 

grading, site development or other surface disturbance (e.g., driving over vegetation). As shown in 

table 9-51 below, only a small percentage of these vegetation communities would be affected by the 

facility actions in Curry Village. Impacts to meadow habitat would occur in a small meadow area 

currently disconnected from the larger Stoneman Meadow to the north by Happy Isle Loop Road. In 

addition, vegetation communities at Curry Village are adjacent to already developed areas, and 

therefore currently experience high levels of visitation and human-related impacts such as vegetation 

trampling and soil compaction. Therefore, losses of vegetation communities, while long-term, would 

be local, adverse and minor. 

Direct impacts to vegetation, including trampling or removal of rooted vegetation, would cause a 

reduction of total numbers of plants and/or a reduction or loss of total area, diversity, vigor, structure, 

or function of vegetative habitat. Direct impacts could also include decrease plant vigor or health from 

reduced water availability or dust accumulation on photosynthetic surfaces. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-328 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

TABLE 9-51: VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR USE AND 

FACILITIES AT CURRY VILLAGE & CAMPGROUNDS – ALTERNATIVE 6 

Vegetation/Wetland Type Acres 

Percent of Vegetation/Wetland 

Type Affected in Segmenta

Segment 2 

Meadow 0.03 <0.1% 

Lower Montane Coniferous 6.35 <0.1% 

Redevelopmentb 1.97 N/A 

Wetland (Palustrine Emergent) 0.04 <0.1% 

Wetland (Riverine Intermittent) 0.02 <0.1% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 

Vegetation that would be removed at Curry Village under Alternative 6 would not substantially 

fragment existing native vegetation communities, reduce species diversity, or substantially reduce the 

overall size or quality of native plant communities in Yosemite Valley, as new construction would 

primarily occur in or adjacent to previously disturbed locations or in more resilient upland habitat. 

Wetlands would be avoided during construction activities. Adherence to proposed mitigation 

measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as applicable (see 

Appendix C), and avoidance of the removal of vegetation where possible, would reduce impacts to 

local, long-term, minor and adverse. 

Construction activities at Curry Village would result in direct, permanent losses of federally protected 

wetlands. Impacts to wetlands would occur in palustrine emergent wetlands associated with Stoneman 

Meadow and intermittent channels flowing through the area. Approximately 0.06 acres of potentially 

jurisdictional wetland features would be directly and permanently impacted by the proposed actions 

under Alternative 6. Losses to these wetlands would occur through site clearing, filling, grading, and 

subsequent development. Construction activities may also generate indirect impacts to wetlands 

including potential modifications to flow, circulation, hydroperiod, or other aspects of the hydrologic 

regime, and increases in sedimentation due to ground disturbance associated with construction. 

However, post-construction, temporarily impacted areas would be restored. Wetlands that cannot be 

avoided and would be permanently filled must be compensated to result in “no net loss” of wetlands. 

Adherence to proposed mitigation measures MM-HYD-1, MM-VEG-1, and MM-VEG-4 through 

MM-VEG-7, as applicable (see Appendix C), and avoidance of wetlands during construction where 

possible, would reduce impacts to wetlands to local, long-term, minor and adverse. 

Camp 6 and Yosemite Village. Near-term specific project-level actions under Alternative 6 in 

Segment 2 related to managing visitor use and facilities at Camp 6 and Yosemite Village include measures 

to formalize and relocate parking facilities 150 feet away from the river in order to facilitate riparian 

restoration goals. The Camp 6/Village Center Parking Area would be formalized to include 850 

designated parking spaces by redeveloping part of the current administrative footprint. In addition, 

100 parking spaces would be added at Yosemite Village. A pedestrian underpass and two roundabouts 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 6 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-329

(one at the Village Drive/Northside Drive intersection and one at the Sentinel Drive/Northside Drive 

intersection) would be constructed to address traffic congestion and pedestrian/vehicle conflicts. A 

three-way intersection would be added at Sentinel Drive and the entrance to the parking area to improve 

traffic flow and alleviate congestion. Expanded parking area and new road construction activities at 

Yosemite Village would result in direct temporary and permanent losses of native vegetation and 

wetlands as well as redevelopment of existing disturbed areas (see table 9-52). 

TABLE 9-52: VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR USE AND 

FACILITIES AT CAMP 6 AND YOSEMITE VILLAGE – ALTERNATIVE 6 

Vegetation/Wetland Type Acres 

Percent of 

Vegetation/Wetland Type 

Affected in Segmenta

Segment 2 

Meadow 0.28 <0.1% 

Lower Montane Coniferous 12.22 0.2% 

Lower Montane Broadleaf 0.81 <0.1% 

Redevelopmentb 14.18 N/A 

Wetland (Palustrine Emergent) 1.21 0.4% 

Wetland (Palustrine Forested) 0.96 0.8% 

Wetland (Riverine Intermittent) 0.39 0.3% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 

As noted in table 9-52, over half of the area affected by the above actions would occur at sites that are 

already developed. Outside of previously developed areas, impacts to vegetation would occur almost 

entirely in lower montane broadleaf forest and lower montane coniferous forest; these types are among 

the most dominant native vegetation communities in Segment 2. Impacts to meadow habitat would occur 

in an area currently impacted by its proximity to Sentinel Drive. Losses to these communities would 

occur through vegetation clearing, grading, site development or other surface disturbance (e.g., driving 

over vegetation). As shown in table 9-52, only a small percentage of these vegetation communities would 

be impacted by the actions at Camp 6 and Yosemite Village. In addition, potentially affected vegetation 

communities are adjacent to already developed areas, and therefore experience high levels of visitation 

and human-related impacts such as vegetation trampling and soil compaction. Therefore, losses of 

vegetation communities, while long-term, would be local, adverse and minor. 

Vegetation that would be removed at Camp 6 and Yosemite Village under Alternative 6 would not 

substantially fragment existing native vegetation communities, reduce species diversity, or substantially 

reduce the overall size or quality of native plant communities in Yosemite Valley, as new construction 

would primarily occur in or adjacent to previously disturbed locations or in more resilient upland 

habitat. Adherence to proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 

through MM-VEG-7, as applicable (see Appendix C), and avoidance of the removal of vegetation 

where possible, would reduce impacts to local, long-term, minor and adverse. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-330 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Parking areas and new road construction activities at Camp 6 and Yosemite Village would result in 

direct, permanent losses of federally protected wetlands. Impacts to wetlands would occur in 

palustrine emergent wetlands located adjacent to the Northside Drive and Sentinel Crossover 

intersection, palustrine forested wetlands associated with the Merced River, and intermittent channels 

flowing through the area. Approximately 2.56 acres of potential jurisdictional wetland features would 

be directly and permanently impacted by the proposed actions under Alternative 6. Losses to these 

wetlands would occur through site clearing, filling, grading, and subsequent development. 

Construction activities may also generate indirect impacts to wetlands including potential 

modifications to flow, circulation, hydroperiod, or other aspects of the hydrologic regime, and 

increases in sedimentation due to ground disturbance associated with construction. However, postconstruction, temporarily impacted areas would be restored. Wetlands that cannot be avoided and 

would be permanently filled must be compensated to result in “no net loss” of wetlands. Adherence to 

proposed mitigation measures MM-HYD-1, MM-VEG-1, and MM-VEG-4 through MM-VEG-7, as 

applicable (see Appendix C), and avoidance of wetlands during construction where possible, would 

reduce impacts to wetlands to local, long-term, moderate and adverse. 

Yosemite Lodge and Camp 4. Actions under Alternative 6 in Segment 2 related to managing visitor 

use and facilities at Yosemite Lodge and Camp 4 include: the removal of old and temporary housing at 

Highland Court and the Thousands Cabins; the construction of two new concessioner housing areas 

and the construction of 78 employee parking spaces; redevelopment west of Yosemite Lodge to 

provide an additional 300 day use parking spaces and area for 15 tour buses; relocation of existing tour 

bus drop off area to Highland Court to provide 3 bus loading/unloading spaces; and the construction 

of a pedestrian underpass to alleviate pedestrian/vehicle conflicts. 

Like other proposed facility projects, construction activities at Yosemite Lodge would result in direct 

temporary and permanent losses of native vegetation and wetlands as well as the redevelopment of 

existing disturbed areas (see table 9-53). Impacts to vegetation would occur in lower montane 

coniferous forest, the dominant natural vegetation community in Segment 2, and to a much lesser 

extent in lower montane broadleaf forest. Losses would occur through vegetation clearing, grading, 

site development or other surface disturbance (e.g., driving over vegetation). As shown in table 9-53, 

only a small percentage of these vegetation communities would be impacted. In addition, potentially 

affected vegetation communities are adjacent to already developed areas, and therefore experience 

high levels of visitation and human-related impacts such as vegetation trampling and soil compaction. 

Therefore, losses of vegetation communities, while long-term, would be local, adverse and minor. 

Like other development actions proposed under this alternative, vegetation that is removed at 

Yosemite Lodge and Camp 4 under Alternative 6 would not substantially fragment existing native 

vegetation communities, reduce species diversity, or substantially reduce the overall size or quality of 

native plant communities in Yosemite Valley, as new construction would primarily occur in or 

adjacent to previously disturbed locations or in more resilient upland habitat. Wetlands would be 

avoided during construction activities. Adherence to proposed mitigation measures MM-GEO-1, 

MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as applicable (see Appendix C), and avoidance of 

the removal of vegetation where possible, would reduce impacts to local, long-term, minor and 

adverse. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 6 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-331

TABLE 9-53: VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR USE AND 

FACILITIES AT YOSEMITE LODGE AND CAMP 4 – ALTERNATIVE 6 

Vegetation/Wetland Type Acres 

Percent of 

Vegetation/Wetland Type 

Affected in Segmenta

Segment 2 

Lower Montane Coniferous 15.47 0.2% 

Lower Montane Broadleaf 1.73 <0.1% 

Redevelopmentb 3.69 N/A 

Wetland (Palustrine Emergent) 0.01 <0.1% 

Wetland (Riverine Intermittent) 0.03 <0.1% 

Wetland (Riverine Perennial) 0.01 <0.1% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the 

segment. b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 

Construction activities at Yosemite Lodge and Camp 4 would result in direct, permanent losses of 

federally protected wetlands. Impacts to wetlands would occur in palustrine emergent wetlands and 

along the Merced River and in intermittent channels flowing through the area. Approximately 0.05 acres 

of potentially jurisdictional wetland features would be directly and permanently impacted by the 

proposed actions under Alternative 6. Losses to these wetlands would occur through site clearing, filling, 

grading, and subsequent development. Construction activities may also generate indirect impacts to 

wetlands including potential modifications to flow, circulation, hydroperiod, or other aspects of the 

hydrologic regime, and increases in sedimentation due to ground disturbance associated with 

construction. However, post-construction, temporarily impacted areas would be restored. Wetlands that 

cannot be avoided and would be permanently filled must be compensated to result in “no net loss” of 

wetlands. Adherence to proposed mitigation measures MM-HYD-1, MM-VEG-1, and MM-VEG-4 

through MM-VEG-7, as applicable (see Appendix C), and avoidance of wetlands during construction 

where possible, would reduce impacts to wetlands to local, long-term, minor and adverse. 

In summary, as shown in table 9-54, actions to manage visitor use and facilities would result in the loss 

of 36.89 acres of vegetation primarily located near previously developed areas, resulting in long-term, 

local, minor, adverse impacts to these communities. Actions to manage visitor use and facilities would 

result in the loss of 2.67 acres of potentially jurisdictional wetlands. 

Segment 2 Impact Summary: Actions to protect and enhance river values within Segment 2 under 

Alternative 6 would result in the restoration of 156 acres of vegetation and 37.32 acres of wetland, 

resulting in long-term, segmentwide, major, beneficial impacts on vegetation and wetlands. Actions to 

manage visitor use and facilities would result in the loss of 36.89 acres of vegetation primarily located 

near previously developed areas, resulting in long-term, local, minor to moderate, adverse impacts to 

these communities. Actions to manage visitor use and facilities would result in the loss of 2.67 acres of 

potentially jurisdictional wetlands. 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-332 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

TABLE 9-54: SUMMARY OF VEGETATION AND WETLAND IMPACTS FROM ACTIONS TO MANAGE VISITOR 

USE AND FACILITIES – ALTERNATIVE 6 

Vegetation/Wetland Type Acres 

Percent of 

Vegetation/Wetland Type 

Affected in Segmenta

Segment 2 

Meadow 0.31 <0.1% 

Lower Montane Coniferous 34.04 0.5% 

Lower Montane Broadleaf 2.54 <0.1% 

Redevelopmentb 19.84 N/A 

Wetland 2.67 0.5% 

a This is a comparison of the acres of vegetation/wetland impacted to the total acres of that vegetation/wetland type in the segment. 

b Redevelopment refers to existing developed areas that will be rebuilt. 

SOURCE: NPS 2012c 

Segments 3 and 4: Merced Gorge and El Portal 

Impacts of Actions to Protect and Enhance River Values 

Currently, vehicles park under the dripline of the 38 valley oak trees. This practice compacts soil under 

the trees, affecting root health, water uptake, and soil aeration. Additionally, existing development and 

trampling in the vicinity limits the area where oak seedlings can be recruited. Under Alternative 6, 

valley oaks in El Portal would be enhanced by creating an oak recruitment area of one acre in Old El 

Portal in the vicinity of the current bulk fuel storage area, including the adjacent parking lots. Parking 

and new building construction within the oak recruitment area would be prohibited. Nonnative fill 

would be removed and soils decompacted. Appropriate native understory plant species would be 

planted. The fuel storage area would be relocated outside of the river corridor. Overall, these actions 

would result in local, long-term, moderate, beneficial impacts on valley oaks in El Portal. 

The types of habitat that would be affected by restoration actions in Segment 4, as well as the types of 

habitat that would be enhanced or restored, are summarized in tables 9-55 and 9-56. A total of 

12 acres of vegetation would be restored in Segment 4, including 0.05 acre of wetland (this includes 

restoration actions common to Alternatives 2-6). 

TABLE 9-55: SEGMENT 4 VEGETATION RESTORATION UNDER ALTERNATIVE 6a

Current Vegetation Acres 

Current 

Habitat Type Acres

Proposed Future 

Habitat Type 

Acres Restored 

or Enhanced 

Valley oak woodland alliance 1 Foothill broadleaf 1 Valley oak woodland 1 

canyon live oak-(Ponderosa 

pine-incense cedar) forest 

superassociation 

11 Lower montane 

broadleaf 11 Lower montane broadleaf 11 

Total 12 12 12 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 6 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-333

TABLE 9-56: SEGMENT 4 WETLAND RESTORATION UNDER ALTERNATIVE 6 

Wetland Type Acres 

Segment 4 

Palustrine Emergent 0.001 

Palustrine Forested 0.05 

Total amount of wetlands restored 0.05 

SOURCE: NPS 2012c 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Under Alternative 6, day parking would be expanded by 200 parking spaces at the Abbieville site; this 

area would primarily be used for visitor access to Yosemite Valley. NPS employee housing would be 

added to Abbieville, El Portal Village Center, and Rancheria Flat. While all new units would be built 

outside of the 100-year floodplain, they would fall within the river corridor. This increase in capacity 

in El Portal is a function of the decrease in employee housing capacity in the Valley (Segment 2). The 

addition of employee housing and park facilities development would increase the total built 

environment within Segment 4. 

Relocation of facilities to other locations within the corridor could have long-term, negligible to 

moderate, adverse effects on vegetation depending on site-specific conditions and project design. 

Local, minor to moderate, short-term, adverse effects could occur from construction and demolition 

of facilities along the Merced River. Vegetation that is removed under Alternatives 2–6 would not 

substantially fragment existing native vegetation communities, reduce species diversity, or 

substantially reduce the overall size or quality of native plant communities at El Portal, as new 

construction would primarily occur in or adjacent to previously disturbed locations or in more 

resilient, upland habitat. Wetlands would be avoided during construction activities. Adherence to 

proposed mitigation measures MM-GEO-1, MM-HYD-1, and MM-VEG-1 through MM-VEG-7, as 

applicable (see Appendix C), and avoidance of the removal of vegetation where possible, would reduce 

short-term impacts to minor and adverse. Overall, these actions would result in local, short-term, 

minor, adverse impacts on plant communities in El Portal. 

Segments 3 and 4 Impact Summary: Actions to protect and enhance river values within Segments 3 

and 4 would result in the restoration of 12 acres of vegetation and 0.05 acres of wetland, resulting in 

long-term, local, moderate, beneficial impacts on vegetation and wetlands. Actions to manage visitor 

use and facilities would result in short-term, local, minor, adverse impacts to vegetation and wetlands. 

Segments 5, 6, 7, and 8: South Fork Merced River 

Impacts of Actions to Protect and Enhance River Values 

The Wawona Golf Course would not be removed under Alternative 6, and therefore effects related to 

its continued operation would be the same as described for Alternative 1. Actions specifically targeted 

to protect culturally sensitive areas would benefit vegetation and wetlands as well, including the 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-334 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

relocation or removal of select campsites and stock campground sites that are within 100 feet of the 

river or in culturally sensitive areas. The removal of select camp sites within the floodplain would 

result in local, long-term, minor, beneficial impact on vegetation and wetlands. 

The types of habitat that would be affected by these restoration actions in Segment 7, as well as the types 

of habitat that would be enhanced or restored, are summarized in table 9-57. A total of three acres of 

vegetation would be restored in Segment 7 (this includes restoration actions common to Alternatives 2-6). 

TABLE 9-57: SEGMENT 7 VEGETATION RESTORATION UNDER ALTERNATIVE 6a

Current Vegetation 

and Acreage Acres 

Current 

Habitat Type Acres

Proposed Future 

Habitat Type 

Acres Restored 

or Enhanced 

Ponderosa pine woodland 

alliance 1 

Lower montane 

needleleaf 3 

Riparian: cottonwood, 

willow, mix of upland 

deciduous & 

coniferous forest 

3 

Ponderosa pine-incense cedar 

forest alliance 2 

Total 3 3 3 

a Left four columns are the existing vegetation and general vegetation type and corresponding acres of each. Right two columns are the 

habitat type and acreage that the proposed restoration would restore or enhance. 

Biological Resource Actions. Specific projects to protect and enhance the river’s biological values 

that would occur within Segment 7 under Alternative 6 include the relocation of stock use campsites 

from sensitive resource areas to Wawona Stables. Overall, this action would result in a local, long-term, 

minor, beneficial impact on plant communities and wetlands in Wawona. 

Impacts of Actions to Manage User Capacities, Land Use, and Facilities 

Under Alternative 6, the operations of the Wawona stables would be eliminated and two stock 

campsites would be relocated to this area from the current Wawona stock camp. Thirteen campsites in 

the Wawona Campground would be removed from within 100 feet of the river or from cultural sites. 

The area would be restored. Soils would be decompacted and the area would be replanted with 

riparian vegetation. This would reduce visitor use in this area, resulting in a decrease of vegetation 

trampling. Overall, these actions would result in a local, long-term, minor, beneficial impact on plant 

communities and wetlands in Wawona. 

Wawona Campground. Facilities actions at the Wawona Campground would involve removal of 13 

sites that are either within the 100-year floodplain or in culturally sensitive areas. Overall, these actions 

would result in a local, long-term, minor, beneficial impact on plant communities and wetlands in 

Wawona. 

Segments 5, 6, 7 and 8 Impact Summary: Actions to protect and enhance river values within 

Segments 5, 6, 7 and 8 under Alternative 6 would result in the restoration of three acres of vegetation, 

resulting in long-term, segmentwide, minor, beneficial impacts on vegetation and wetlands. Actions to 

manage visitor use and facilities would result in long-term, local, minor, beneficial impacts to 

vegetation and wetlands. 
Analysis Topics: Natural Resources 

Vegetation and Wetlands – Alternative 6 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS 9-335

Summary of Impacts from Alternative 6: Diversified Visitor Experiences and Selective 

Riverbank Restoration 

Alternative 6 would restore approximately 170 acres of vegetation, including 37.37 acres of wetlands, 

as a result of actions common to Alternatives 2-6 and those specific to Alternative 6. Actions to manage 

visitor use and facilities would result in the loss of approximately 36.89 acres of vegetation and the 

permanent loss of 2.67 acres of potentially jurisdictional wetlands as a result of actions specific to 

Alternative 6.Past development and human activity in the Merced River corridor have in some cases 

adversely affected vegetation communities and regional vegetation patterns. Actions associated with 

Alternative 6 are expected to have corridorwide, long-term, moderate, beneficial impacts on 

vegetation in the Merced River corridor. As described above, many of the actions in Alternative 6 

would address existing adverse impacts on vegetation communities. This includes actions that are 

targeted to improve wetland, riparian, and meadow communities where these habitats are near or 

adjacent to existing developments and areas subject to high visitor use. Additionally, the park would 

implement measures to increase channel free flow, improve water quality, and reduce erosion and 

scouring. Notable actions the park would implement under Alternative 6 include 

 restricting recreational use of rivers and riverbanks to reduce riverbank erosion 

 removing, restoring, relocating, or repurposing park facilities to efficiently utilize park 

facilities and reduce the built environment within the park; some facilities would be built to 

accommodate visitors or employees 

 managing for an increase (4%) in total daily visitors to the park and visitor demands for day 

parking space, lodging, and camping space 

 removing selected facilities within 100 feet of the Merced River and restoring riverbanks, 

meadows, and riparian habitat 

 enhancing meadow, riparian, and river hydrologic function, complexity, and connectivity 

 improving the free flow, complexity, and water quality of the Merced River 

Generally, Alternative 6 is focused on restoration of meadow, riparian, and riverbank habitats in 

Yosemite Valley (Segment 2); retaining most park facilities but removing selected facilities that are 

located within 100 feet of the Merced River and are jeopardized by flood; repurposing park facilities to 

improve efficiency of use; and providing adequate lodging, camping, and parking space for visitors and 

employees. Additionally, the park would continue to provide river access to visitors in designated 

areas, and continue to protect the river and riverbanks by requiring permits or limiting use of put-in 

areas. Alternative 6 would allow for a significant increase in total daily visitations to the park and park 

infrastructure (lodging, camping space, and parking lots) would be retained or expanded in selected 

locations to accommodate increased demand. Adverse effects from these actions would be associated 

with the active construction or restoration phase, and would be local, short-term, and negligible to 

moderate, depending on the type of project and location. Although some habitat would be restored 

and fragmentation would be reduced in selected areas, increase in visitors to the park accompanied by 

continued operation of most park facilities and construction of new facilities would result in adverse 

impacts on vegetation communities over the long-term where visitor use is concentrated. These effects 

would be most prominent in areas of high human use, such as Yosemite Valley and Wawona 
AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES

9-336 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

(Segments 2 and 7).When combined, the long term effect of Alternative 6 would be a corridorwide, 

moderate beneficial impact on vegetation. 

Cumulative Impacts from Alternative 6: Diversified Visitor Experiences and Selective 

Riverbank Restoration 

The past, present, and reasonably foreseeable plans and projects that could have a cumulative impact 

on vegetation resources are the same as those listed under the No Action Alternative. Alternative 6 

would result in segmentwide, long-term, minor, beneficial impacts on vegetation communities within 

the Merced River corridor. These actions are focused on restoring and improving aquatic, meadow, 

and riparian habitat quality within the Merced River corridor. The past, present, and future actions in 

the region would have varying effects on vegetation and wetlands, with some projects restoring or 

enhancing vegetation and wetlands, and many others resulting in the loss or decline of vegetation and 

wetlands. For projects that would result in the loss of wetland features regulated under section 404 of 

the CWA, losses would be typically compensated at a ratio of 1:1 (no net loss). Compensation typically 

occurs through creation or enhancement of wetlands either on-site or at a designated mitigation bank. 

However, even with these protections in place, wetlands may be lost over time through unregulated 

activities or negatively impacted through nonpoint source pollution, nonnative species, and changes in 

surface and subsurface hydrology over time. 

The actions under Alternative 6 would have long-term, beneficial effects on vegetation and wetlands, 

including vegetation-related ORVs, within the Merced River corridor. However, in relation to past, 

present, and reasonably foreseeable future actions throughout the Sierra Nevada and larger region 

(e.g., introduction and spread of nonnative species, direct displacement of vegetation by structures), 

the actions under Alternative 6 would have a minimal beneficial effect. Overall, cumulative actions on 

vegetation and wetlands would result in long-term, minor, adverse effects on regional vegetation 

patterns.