Merced Wild and Scenic River Comprehensive Management Plan / DEIS

APPENDIX L 

DETERMINATION OF EXTENT NECESSARY 

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

APPENDIX L 

DETERMINATION OF THE EXTENT NECESSARY FOR 

COMMERCIAL SERVICES IN THE WILDERNESS SEGMENTS 

OF THE MERCED WILD AND SCENIC RIVER CORRIDOR 

PART 1: INTRODUCTION 

The vast majority of Yosemite National Park (95%) was designated as federally protected wilderness 

by the California Wilderness Act of 1984.1 Congress delegated management responsibility for 

Yosemite Wilderness to the National Park Service (NPS). In furtherance of its wilderness management 

responsibilities, the NPS has adopted a trailhead quota system to limit overnight visitation, 

implemented an extensive educational program to teach visitors how to minimize their impacts, 

promulgated a variety of specific regulations that mandate low impact practices, and instituted 

numerous monitoring programs to assess wilderness character and track potential threats to that 

character. 

The National Park Service has not yet completed an Extent Necessary Determination for commercial 

services for Yosemite’s entire designated wilderness. The need for this type of specialized finding has 

only recently been articulated, stemming from a 2004 decision by the U.S. Court of the Appeals for the 

Ninth Circuit in the case High Sierra Hikers Association v. Blackwell.

2 In the Blackwell decision, the 

Ninth Circuit ruled that wilderness managing agencies must complete a specialized finding of necessity 

prior to authorizing commercial services in wilderness. This finding must be made after considering 

the extent to which commercial services are necessary to achieve the purposes for which the affected 

wilderness area was set aside. Congress directed that Yosemite’s wilderness be set aside for 

recreational, scenic, scientific, educational, conservation, and historical use purposes. This document 

evaluates the necessity for commercial services for designated wilderness portions of the Merced River 

corridor in light of these purposes.

The most appropriate framework for completing an assessment of an Extent Necessary Determination 

for commercial services in wilderness is in the park’s wilderness stewardship plan, where commercial 

services will be addressed comprehensively for Yosemite’s entire wilderness. Yosemite National Park 

has appropriated funding for updating its Wilderness Stewardship Plan, and has begun the initial steps 

in the planning process. The plan, however, will not be ready for public review for several more years. 

Rather than await the development of a new Wilderness Stewardship Plan, the park has elected to 

analyze commercial services in the wilderness portions of the Merced Wild and Scenic River corridor 

at this time and provide the public with an opportunity to comment. 

 

1 California Wilderness Act, Public Law No. 98-425 (1984)

2 See, e.g., High Sierra Hikers Association v. Blackwell, 390 F.3d 630 (9th Cir. 2004); High Sierra Hikers Association v. 

Weingardt, 521 F. Supp. 2d 1065 (2007). 
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L-2 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

PART 2: PURPOSE OF THIS EXTENT NECESSARY DETERMINATION AND 

RELATIONSHIP TO OTHER PLANS 

The purpose of this document is to determine limits on commercial services in the wilderness sections 

of the Merced River Corridor in accordance with the requirements of the Wilderness Act and NPS 

wilderness management policies. The limits described in this document apply only to the wilderness 

segments of the Merced River corridor. 

As noted above, the NPS is in the early stages of updating the park’s Wilderness Stewardship Plan. 

Limits adopted in this Extent Necessary Determination will be revisited as part of the planning process 

for the Wilderness Stewardship Plan, which will determine the extent of commercial services 

necessary throughout all of Yosemite’s designated Wilderness. There will be many opportunities for 

public involvement in the development of the Wilderness Stewardship Plan, including the ability to 

provide additional input on the amount of commercial services that should be authorized. 

This Extent Necessary Determination is neither a formal element nor a required component of the 

Wild and Scenic Rivers Act as addressed in the Merced Comprehensive River Management Plan. 

Under the Wild and Scenic Rivers Act, the NPS must adopt specific limits on use within the river 

corridor to ensure that the kinds and amounts of visitor use protect and enhance the river’s 

outstandingly remarkable values, free flowing condition and water quality. The MRP’s capacity 

determinations, then, represent the maximum amount of use that can be allowed without degrading 

river values. The user capacities that were established in the MRP planning process were incorporated 

into this Extent Necessary Determination. In sections 7 and 8 below, this document analyzes those 

capacities in accordance with the requirements of Section 4(d) of the Wilderness Act to determine the 

extent to which any portion of the MRP’s numeric use limits should be allocated to commercial service 

users. This Extent Necessary Determination therefore tiers from the capacity determinations in the 

MRP. 

PART 3: LEGAL FRAMEWORK FOR EVALUATING COMMERCIAL 

SERVICES IN WILDERNESS 

A. The Wilderness Act 

The Wilderness Act was passed in 1964 to “secure for the American people of present and future 

generations the benefits of an enduring resource of wilderness.”3 Section 4(c) of the Wilderness Act 

explicitly bars “commercial enterprises within designated wilderness areas.”4 An exception to this ban, 

subject to limitations, is provided for commercial services such as guides and outfitters in section 4 (d) 

6, which states that “commercial services may be performed within the wilderness areas designated by 

this Act to the extent necessary for activities which are proper for realizing the recreational or other 

 

3 Wilderness Act, 16 USC 1131 (a) 

4 Wilderness Act, 16 USC 1133 (c) 
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Wilderness Segments of the Merced Wild and Scenic River Corridor 

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

wilderness purposes of the areas.”5 “Wilderness purposes” are defined in section 4 (b) of the Act as 

“recreational, scenic, scientific, educational, conservation, and historical use.”6

The National Park Service has not issued regulations or formal policy guidance outlining the process 

for authorizing commercial services under Section 4(d) of the Act. However, the U.S. Court of Appeals 

for the Ninth Circuit has issued several decisions interpreting the restrictions on commercial activities 

found in Sections 4(c) and (d) of the Act. These decisions have informed the analysis in this Extent 

Necessary Determination. 

In 2003, the Ninth Circuit, in The Wilderness Society v. U.S. Fish & Wildlife Service, examined the overall 

structure of the Act and found that the Act’s broad mandate to protect wilderness areas was furthered by 

the prohibition provision found in Section 4(c), which among other things, prohibits commercial 

enterprises in wilderness. That prohibition, however, is qualified by the introductory language of 

Section 4(c) which states, “Except as specifically provided for in this [Act] ... there shall be no commercial 

enterprise” within any wilderness area. (Emphasis added.) The exceptions to Section 4(c)’s prohibitions 

are found in Section 4(d), which is entitled “Special provisions.” Of relevance here is the exception 

allowing for commercial services. The commercial services exception is limited in scope. Because of the 

Act’s structure, in which there is a broad prohibition on commercial enterprise in Section 4(c) followed 

by a list of “special provisions” in Section 4(d), the Court concluded that the exceptions found in 

Section 4(d) are most properly read as a series of limited and express exceptions to the general 

prohibition found in Section 4(c) on commercial enterprises in wilderness.7

In 2004, the Ninth Circuit issued an opinion, High Sierra Hikers Assn. v. Blackwell, interpreting the 

commercial services exception found in Section 4(d)(6) of the Act. The Court examined the specific 

language of Section 4(d)(6), and in particular the language stating that commercial services may only be 

authorized “to the extent necessary,” as well as relationship between Section 4(d)(6) and other 

provisions of the Wilderness Act. According to the Court, the phrase “to the extent necessary” 

imposed a requirement on wilderness managing agencies to make a “specialized” finding of necessity 

before authorizing commercial services in wilderness. In this specialized finding, the agency must 

“show that the number of permits [or other authorizations] granted was no more than was necessary 

to achieve the goals of the Act.” Although it determined that a specialized finding is required, the 

Court recognized that the Wilderness Act is “framed in general terms and does not specify any 

particular form or content” for the specialized finding. Moreover, the Court recognized that 

wilderness managing agencies are charged with diverse and sometimes conflicting mandates under the 

Act. Agencies are obligated to protect and preserve wilderness areas, but the Act also embraces 

competing directives such as those related to the provision of opportunities for public recreation and 

the discretion to take actions to manage fire and insect risks.8

This Extent Necessary Determination follows the direction provided by these Court opinions. In the 

sections that follow, we identify the types of “activities which are proper for realizing recreational and 

other wilderness purposes” and then determine the numeric amount of commercial services that are 

 

5 Wilderness Act, 16 USC 1133 (d) (5) 

6 Wilderness Act, 16 USC 1133 (b) 

7 The Wilderness Society v. U.S. Fish & Wildlife Service, 252 F.3d 1051, 1062 (en banc) (2003) 

8 High Sierra Hikers Assn. v. Blackwell, 390 F.3d 630 (9th Cir. 2004) 
APPENDIX L 

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

necessary to realize these purposes, ensuring that the number authorized is no more than necessary so 

that wilderness character will be preserved. 

B. NPS Wilderness Management Policies 

Commercial services must be consistent with the application of the minimum requirement concept 

and with the objectives of the park’s Wilderness Management Plan.9 See Section 9 of this document for 

the application of the minimum requirement concept for commercial allocation. 

C. Yosemite Wilderness Management Plan 

The Yosemite Wilderness Management Plan states that commercial packers “...may be restricted to 

designated park areas.”10

PART 4: USER CAPACITY IN WILDERNESS 

In the Yosemite Wilderness, wilderness character is preserved in part through the use of the trailhead 

quota system, which limits the amount overnight visitation through the use of a wilderness permit 

system. In order to preserve wilderness character, NPS must ensure that natural resources are 

protected from damage that can result from overuse, and that outstanding opportunities for solitude 

are preserved. 

The Yosemite trailhead quota system was developed in the 1970s, prior to wilderness designation.11

The backcountry area of the park was divided into travel zones. For each zone a capacity was set based 

on the number of acres and miles of trails and desired sociological densities for campsites and trails. 

The capacities were then adjusted to protect ecological resources. For example, capacities were 

adjusted in zones with ecosystems that were rare or vulnerable (such as those with subalpine 

meadows), or that exhibit fragility or limited resilience following impacts (such as those with alpine 

meadows). Zone capacities have been adjusted periodically to reflect new or changed scientific 

findings regarding ecosystem health and the effect of patterns of visitor use on resources. 

In concert with these zone capacities, the NPS has implemented a trailhead quota system. This type of 

system requires beginning a trip at a certain trailhead on a certain day, but otherwise does not 

generally restrict travel plans. Visitor travel patterns were studied to determine the relationship 

between the various trailheads and the travel zones.12 By studying wilderness visitation travel patterns, 

managers were able to determine the percentage of visitors to each zone that are attributable to each 

trailhead. By limiting the number of individuals who may enter the wilderness from a given trailhead 

 

9 NPS Management Policies 2006 6.4.4. 

10 National Park Service, Wilderness Management Plan, 1989, pg. 21 11 van Wagtendonk, J. W. 1979. A conceptual backcountry carrying capacity model. Proc. 1st. Conf. Sci. Res. in the nat'l. 

Parks. USDI, Nat'l. Park Serv. Trans. and Proc. Series 5:1033-1038. 

12 van Wagtendonk, J.W., and J. M. Benedict. 1980.Wilderness permit compliance and validity. J. Forestry 78(1): 399-

401; van Wagtendonk, J.W., and P. R. Coho. 1986. Trailhead quotas: rationing use to keep wilderness wild. J. Forestry 

84(11): 22-24. 
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Wilderness Segments of the Merced Wild and Scenic River Corridor 

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

on a given day, managers limit the number of visitors to each zone such that the wilderness character 

of the zone, including both the physical resources and the outstanding opportunities for solitude are 

maintained in accordance with law. 

As part of the Merced River Plan, the NPS reevaluated the wilderness zone capacities within the 

Merced River Corridor in light of the Wild and Scenic Rivers’ Act mandate to protect and enhance 

Outstandingly Remarkable Values and the river’s free-flowing condition. The zone capacities adopted 

for the river corridor guided the Extent Necessary Determination process. For six of the eight zones 

that include the Merced River corridor, the zone is much larger than the corridor. This extent 

necessary determination is for the full geographic extent of all eight zones rather than just the corridor. 

In addition to the use limits set by the trailhead quota system additional limits that relate to wilderness 

will be in place under the Merced Wild and Scenic River Plan. For example, a capacity on grazing 

nights for pack stock is being established for the meadow near the Merced Lake Ranger Station. 

PART 5: DEFINITIONS 

A. Definition of Proper Activities 

Section 4 (d) (6) only allows commercial services which are “proper for realizing the recreational or 

other wilderness purposes of the areas.” Not all activities are proper or allowable in wilderness areas. 

Section 4(c) of the Wilderness Act prohibits public use of motor vehicles, other forms of mechanical 

transport, motorized equipment, and landing of aircraft.13 The 2006 Management Policies provide 

additional guidance on the types of activities that are proper in park wilderness areas. NPS policy 

states that recreational uses in wilderness will be of a nature that: 

 Enables the areas to retain their primeval character and influence; 

 Protects and preserves natural conditions; 

 Leaves the imprint of man’s work substantially unnoticeable; 

 Provides outstanding opportunities for solitude or primitive and unconfined types of 

recreation; and 

 Preserves wilderness in an unimpaired condition14. 

These restrictions apply equally to commercial and noncommercial public use. In the Yosemite 

Wilderness, proper activities are those traditionally associated with wilderness recreation, including 

hiking, backpacking, stock use, rock climbing, photography, nature study, and others. Improper (and 

illegal) activities include snowmobiling, mountain biking, skateboarding, and others. For a commercial 

service to be considered, it must first be related to an activity that is proper in wilderness. Therefore, 

the only commercial services considered in this document are those related to the types of activities 

found to be proper in Yosemite wilderness. 

 

13 16 USC 1133 (c). 

14 NPS Management Policies 2006, 6.4.3. 
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L-6 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

The Wilderness Act directs that wilderness areas be administered “so as to provide...for the gathering 

and dissemination of information regarding their use and enjoyment as wilderness”15 The making of 

films in wilderness is considered proper for realizing the educational and scenic purposes. 

B. Definition of Commercial Services 

Before the National Park Service can determine the types of commercial services that are necessary to 

further wilderness purposes, we must first determine which services are commercial in nature and 

which are not. The Wilderness Act does not define the term “commercial service.” When Congress has 

failed to include definitions of important terms in a statute, agencies may rely on commonly accepted 

definitions. The word “commercial” is commonly defined as (1) “[o]f or relating to commerce,” i.e., 

“[t]he buying and selling of goods, esp. on a large scale: business,” (2) “[e]ngaged in commerce,” 

(3) “[i]nvolved in work designed or planned for the mass market,” or (4) [h]aving profit as a primary 

aim.”16 The word “service” is commonly defined as, “the organized system of apparatus, appliances, 

employees, etc., for supplying some accommodation required by the public” or “the performance of 

any duties or work for another; helpful or professional activity.”17 Activities that are necessary and 

proper for realizing wilderness purposes will be evaluated to determine whether they reflect 

consistent, commonly understood usage of the terms “commercial” and “services.” 

In addition, our determination as to what constitutes a “commercial service” is guided by an analysis of 

the primary purpose and effect of each service. This further layer of analysis, focused on purpose and 

effect, is supported by judicial precedent.18 While some services are conducted for more than one 

purpose and may have more than one effect, the focus of our analysis is on ascertaining the primary 

reason for the service. Incidental or subsidiary purposes and effects do not dictate that a service be 

categorized as commercial. 

For purposes of this document, a commercial service is one that relates to or is connected with 

commerce wherein work is performed for another person or entity, if the primary purpose is the 

experience of wilderness through support provided for a fee or charge and if the primary effect 

is that the wilderness experience is guided and shaped through the use of support services 

provided for a fee or charge. 

The form of the organization providing the service is also not dispositive of whether the organization is 

offering a commercial service, for example whether it is a non-profit or not-for-profit. Rather, the 

definitions above, including an analysis of the activity’s purpose and effect, will guide a determination 

of whether a service is commercial or not. 

Commercial services may be authorized under a number of different legal authorities, using a number 

of different instruments. Of relevance to designated wilderness areas within Yosemite National park 

are concession contracts, commercial use authorizations, and special use permits. 

 

15 Wilderness Act, (16 USC 1131 (a)).

16 Webster’s II New College Dictionary 225 (1995); accord Merriam-Webster’s Collegiate Dictionary 230 (2000). See

Wilderness Society v. U.S. Fish and Wildlife Service, 353 F.3d. 1051, 1061 (9th Cir. 2003) 

17 www.dictionary.com. 18 Wilderness Society v. U.S. Fish and Wildlife Service, 353 F.3d. 1051, 1061 (9th Cir. 2003). 
Determination of the Extent Necessary for Commercial Services in the 

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

1. Authorization Mechanisms for Commercial Services 

a. Concessions Contracts and Commercial Use Authorizations: 

Services authorized under concessions contracts and commercial use authorizations are considered 

commercial services because the entities holding these authorizations are businesses engaged in 

commerce, they provide a service to the public, members of the public who use these services 

experience Yosemite wilderness directly as a result of this commercial support, and employees of the 

concessioner and CUA holder direct and guide the wilderness experience of the trip participants. 

CUAs holders who lead either stock or hiking trips (hiking trips include those that focus on fishing, 

photography, Nordic skiing, and other appropriate activities which do not involve stock transport or 

technical climbing) are considered providers of commercial services, as is the primary park 

concessioner, which leads stock, hiking, and climbing trips in wilderness. 

b. Special Use Permits: 

Special Use Permits are used to authorize a wide range of activities, many of which are not commercial. 

Because Special Use Permits are issued on a case by case basis, it is not possible to evaluate all of the 

different activities that might be requested in a special use permit in advance; however, commercial 

filming permits (one type of Special Use Permit) are discussed below. When a request for another type 

of Special Use Permit in wilderness is received, it will be evaluated in accordance with the criteria 

above to determine whether the activity constitutes a commercial service. If it does, a permit will only 

be authorized in accordance with the procedures set out below in Sections 8. 

2. Application of the Purpose and Effect Analysis 

For the majority of traditional wilderness outfitting and guide services the determination of 

commerciality is straightforward. The commerciality of some uses is not as clear, however, and those 

uses are analyzed here. 

a. Scientific Research: 

Scientific research performed by faculty, postdoctoral fellows, or students enrolled in degree-granting 

programs in accredited colleges and universities or holding appointments with governmental agencies 

or scientific research institutions, even when accompanied by pack stock support, will typically not be 

considered commercial. Research trips using pack stock support would normally not be classified as a 

commercial service trip because the primary purpose and effect of the trip is the enhancement of 

scientific understanding of park resources, not commercial interests. The NPS will review requests for 

scientific research permits that involve the support of commercial outfitters to determine whether the 

trip is commercial. In the event that a research trip is categorized as a commercial service, it will be 

allowed in accordance with the procedures set out below in Sections 8.19

 

19 Some scientific research could involve a commercial component if it contained an element of “bioprospecting.” Any 

such proposals will be reviewed for legality under the Wilderness Act and commerciality under the guidelines noted 

above. 
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L-8 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

b. Commercial Filming and Photography: 

The NPS allows commercial filming and photography in national parks provided that there would not be 

a likelihood of resource damage, an unreasonable disruption of the public’s use and enjoyment of the 

site, or a health or safety risk to the public.20 Filming involves movement or motion of the subject 

whereas photography does not. The NPS Management Policies define “commercial filming” as “filming 

that involves the digital or film recording of a visual image or sound recording by a person, business, or 

other entity for a market audience.” All commercial filming is subject to permitting requirements, and is 

limited to projects that are necessary or proper for providing educational information about wilderness 

uses, resources or values, or necessary for other wilderness purposes. Still photography is only subject to 

permitting requirements if it takes place in areas not open to the public, involves the use of models or 

props that are not part of the location’s existing setting, or requires NPS oversight. Based on the NPS 

policy cited above, all commercial filming and photography will be treated as a commercial service. 

c. Trips by Educational Institutions: 

Each year, the park receives requests for wilderness trips by student groups from accredited 

educational institutions which are conducting classes for course credit. These institutions range from 

elementary, middle and high schools to colleges and universities. The goal of these trips is to provide 

environmental education to students and to foster self-reliance and other qualities. In some cases, 

employees of the educational institution guide the trip. In others, the school retains the services of an 

institution with expertise in environmental education. NatureBridge, a park partner whose mission is 

environmental education, leads many trips of this type (A small percentage of NatureBridge’s trips are 

not for academic credit and are considered commercial). Trips by accredited academic institutions 

which give course credit for completion, even if accompanied by Yosemite Institute or a similar 

organization, are not considered commercial services for the purposes of this Extent Necessary 

Determination. The primary purpose and effect of these trips is fulfilling academic goals for the 

students involved. The students’ experience is guided and shaped by the institution’s academic goals. 

Support services from environmental education organizations like NatureBridge do not change the 

essential character of the trip, which is academic not commercial. 

C. Definition of Wilderness Purposes 

1. Recreation 

All visitors to the Yosemite Wilderness help to realize the recreational purpose. The recreational 

purpose is realized when people are engaged in proper activities in wilderness. Those activities are 

described in Section 5.A above. Hiking, backpacking, horseback riding, fishing, climbing, nature study, 

and mountaineering are just a few examples of the many ways that visitors help to realize this purpose. 

Yosemite National Park does not allocate capacity to particular wilderness recreational activities.21

 

20 U.S.C. §460l-6d 

21 This approach is reaffirmed by a recent district court ruling which stated: “...neither fishing nor any other particular 

activity is endorsed by the Wilderness Act, nor is the enhancement of any particular recreational potential a necessary 

duty of wilderness area management.” High Sierra Hikers Assn. v. U.S. Forest Service, 436 F.Supp.2d 1117, 1144 (E.D. 

Cal. 2006). 
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Merced Wild and Scenic River Comprehensive Management Plan / DEIS L-9 

2. Education 

While many wilderness visitors are engaged in some type of informal, self-directed education, formal 

education is also necessary to realize the educational purpose. 

Examples of formal education that realize the educational purpose of wilderness include, but are not 

limited to the following: 

“How to” education on such topics as: 

 Equipment selection 

 Navigation 

 Wilderness first aid 

 Travel and camping skills 

More advanced “skills” training on such topics as: 

 Rock climbing 

 Mountaineering 

 Backcountry skiing 

Coursework on wilderness values, ethics or philosophy including: 

 Natural history 

 Human or cultural history 

 Wilderness values 

 Environmental social or political history 

 Environmental philosophy 

Coursework on scientific aspects of wilderness, such as: 

 Biology 

 Geology 

 Zoology 

 Fire ecology 

Programs specifically designed to teach residents of urban areas, particularly youth, wilderness 

skills, including: 

 Self reliance 

 Survival 

 Independence 

 Physical fitness and agility 

 Mental toughness 

 Problem-solving 

 Adaptability 
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L-10 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

Making of educational films about wilderness, including but not limited to those about 

wilderness:22

 Wilderness values 

 Natural history 

 Human or cultural history 

 Famous wilderness defenders such as John Muir 

 Endangered species preservation 

 Instructional films covering wilderness skills and techniques 

Exception: 

 Leave No Trace training is considered a fundamental prerequisite for all wilderness 

visitors and as such will not be considered formal education. 

3. Scenic 

Wilderness possesses a particular type of scenery-natural and untrammeled. The scenic purpose is 

realized when visitors observe the natural landscape of wilderness. It is also realized when people take 

photographs of scenery and share them with others outside of the wilderness. As with the educational 

purpose, however, there is a more formal appreciation of scenery that is enjoyed by photographers and 

other artists. Commercial services provide necessary support for this purpose if they offer 

photography, painting, or even writing workshops that focus on appreciating and interpreting the 

scenery. Commercial filming, videography, audiography, and photography also realize the scenic 

purpose if they focus on wilderness scenery and soundscape. 

4. Conservation 

Conservation means actions that help to maintain the wilderness in a largely natural and untrammeled 

state, with native biodiversity intact and natural processes uninterrupted. 

Examples of activities in wilderness that help to realize the conservation purpose include, but are not 

limited to: 

 Ecological restoration projects 

 Trail building and maintenance 

 Species preservation activities 

 Eradication or removal of non-native invasive species 

Realizing the conservation purpose is primarily an agency responsibility. Occasionally a visitor group 

conducts a “service trip” that includes conservation work. In Yosemite, however, these groups are not 

able to work independently of NPS control and supervision. They are designated as volunteers, and 

are thus agents of the National Park Service. This purpose is realized by the agency, not by commercial 

 

22 Films focused on displaying scenic beauty rather than providing education on a topic may more properly be 

considered to fulfill the “scenic” purpose described below at Section 5.B.3. 
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services. If the primary purpose of the service trip is to construct, implement or maintain a 

conservation project, then the purpose and effect is non-commercial. 

5. Historic 

“Historic uses” are defined as those uses which emphasize the wild, untrammeled, and natural 

character of the land in its historic state. Visitors help to realize the historic purpose when they 

encounter the land as did those of earlier historical periods. The historic purpose is realized by 

maintaining the wilderness character of the land, by primitive recreation in the wilderness, by the 

provision of opportunities for solitude, and by enjoying the scenic wonders of the natural and 

untrammeled landscape. The realization of this purpose is consistent with the realization of the 

conservation and recreational purposes. 

The courts have directly addressed the meaning of “historic uses” as used in the Wilderness Act, and 

have uniformly construed “historic use” to mean use of the primeval or ancient wilderness in its 

natural state. The U.S. Court of Appeals for the 11th Circuit found that “the only reasonable reading of 

“historical use” in the Wilderness Act refers to experiencing the natural, rather than man made, 

features.”23 This decision was followed by the district court in Olympic Park v. Mainella, which held 

that: 

[t]he Park Service references the historic pattern of shelter construction and recreational use 

in concluding that the “setting, association, and feeling are significant aspects of historic use 

within the park” (AR 416-17), but while this may be true, this type of usage is in the past and a 

new value has been placed on the land by the creation of the Olympic Wilderness....a different 

“feeling” of wilderness is sought to be preserved for future generations to enjoy, a place 

“where the earth and its community of life are untrammeled by man” and which retains “its 

primitive character and influence.”24

Thus, “historic use” refers to preserving the wilderness character of the land so that each visitor may 

encounter it in its historic state, as undeveloped as it was when modern humans first experienced it. 

No commercial services are necessary for the realization of the historical purpose because its 

realization is congruent with the realization of the conservation purpose. 

6. Scientific 

The natural and untrammeled qualities of wilderness make an area valuable to science. Realizing the 

scientific purpose means allowing scientific research and monitoring to take place in wilderness. 

Unlike conservation activities, scientific activities fall on a spectrum from administrative to 

independent: Some are conducted by the agency, some are conducted by academics but sponsored or 

overseen by the agency, and some are conducted by independent academics or graduate students. 

Research conducted by or for the NPS is considered administrative, not commercial. On rare 

occasions an independent researcher might require commercial services to pack in supplies. However 

 

23 Wilderness Watch v. Mainella, 2004, need correct cite format, followed by Olympic Park Associates v. Mainella, 2005 

WL 1871114 (D. Wash. 2005) 

24 Olympic Park Associates v. Mainella, 2005 WL 1871114 (D.Wash. 2005) 
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L-12 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

as discussed above in Section 5, the incidental use of pack services to support a research trip typically 

would not convert a research trip into a commercial service. 

In the Yosemite Wilderness, research is reviewed by an interdisciplinary permit committee and limited 

though a process articulated in An Interagency Framework to Evaluate Proposals for Scientific Activities 

in Wilderness.

25 This framework, including the application of the minimum requirement concept, 

provides methods to quantify the impacts and benefits of research, compare costs and benefits, and 

prioritize research proposals. 

PART 6: EXTENT NECESSARY DETERMINATION 

This section describes the thresholds and methods used to determine limits on commercial services in 

the wilderness portions of the Merced River corridor. As noted above, no commercial services are 

needed for the realization of the historic, scientific, or conservation purposes. All proposed 

commercial trips in wilderness will be assessed to see which purposes they fulfill (see section on the 

application process, below). 

A. Overnight Use 

The wilderness portions of the Merced River corridor are overlaid with eight wilderness management 

zones. Each zone has an established capacity and trailhead limits are enforced. The extent necessary 

determination for overnight trips analyzes use in each zone by month. 

1. Recreational Purpose 

Under the Wilderness Act, the NPS can only authorize commercial services in wilderness if they are 

necessary to realize wilderness purposes. Therefore it is important to understand the amount of noncommercial use that is occurring in relation to established capacities. If a wilderness zone is 

substantially full with noncommercial visitors, then commercial visitors are not needed to realize the 

recreational purpose. To determine whether an area is “substantially full,” the following method is 

used: 

Each zone is accessed by a number of trailheads, each with a daily quota for overnight use (see capacity 

discussion above in Part 4). For each zone, permit records for all trailheads that provide more than 

10% of the overnight visitors to that zone are tallied (minus permits for commercial groups) and 

compared to the trailhead quotas. The number of days per month that those trailhead quotas are at 

least 90% full is tallied. Those days are considered “full.” 90% was chosen instead of 100% because 

visitors are frequently turned away before 100% of the quota is reached-for example, if only one spot 

is left, groups of two or greater will be turned away. On many days reserved permits are cancelled, or 

groups with a reservation arrive with a smaller group than planned. When this happens late in the day, 

utilization is slightly less than the quota even though many groups may have been turned away. 

 

25 See Landres, P., Fincher, M., Sharman, L., et al, An Interagency Framework to Evaluate Proposals for Scientific 

Activities in Wilderness, 2009 at wilderness.net/toolboxes. 
Determination of the Extent Necessary for Commercial Services in the 

Wilderness Segments of the Merced Wild and Scenic River Corridor 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS L-13 

This analysis is done by month, using a five year average of wilderness permit data from 2005-2009. If a 

zone is “full” more than 66% of the days in a month, that zone is considered substantially full, and will 

be considered a “restricted” zone. Those zones where the trailheads serving the zone are full 33% to 

65% of the time are “weekend restricted” zones. Typically the full days fall on weekend nights, with 

Fridays and Saturdays the most likely to be substantially full. 

Webster’s Dictionary defines “realized” as “to bring into concrete existence.” It is not necessary that a 

zone be filled to capacity in order for the recreational purpose of that zone to be realized. However, 

“realization” implies a level of “concrete” use beyond the minimum. Many zones are popular 

destinations with great demand for access from both the public and commercial outfitters. A zone 

threshold of 66% for “realization” of the recreational purpose means that all wilderness permits for 

that zone are issued 4.6 days per week throughout the month. This means that every weekend and 

holiday as well as many weekdays is filled to capacity for that zone. Additionally, in many popular 

zones even those days on which utilization falls below 90% it often exceeds 80%. This means that the 

overall percentage of a quota utilized for a given month may be significantly higher than the percentage 

of “full” days. The level at which a purpose is realized necessarily entails an exercise of management 

judgment. This definition of “realization” balances the competing factors of access for commercial 

recreational groups against the overall preference expressed in the Wilderness Act for noncommercial 

recreational visitation. 

A zone threshold of 33% to 65% for a “weekend restricted” zone means that this zone is filled to 

capacity between 10 and 19 days per month. This means that every weekend and holiday is filled to 

capacity for that zone. Noncommercial public recreational demand is dramatically increased on 

weekends. The “weekend restricted” designation maintains commercial recreational access to 

desirable areas by permitting it on weekdays, when it helps realize the recreational purpose, while 

maximizing noncommercial recreational access on weekends. 

The results of the overnight commercial recreational capacity analysis are shown on map 1. Overnight 

commercial groups will be allowed to travel through restricted or weekend restricted zones as long 

they spend the night outside of such zones. 

2. Educational Purpose 

The educational purpose is considered realized when there are opportunities for both informal and 

formal education taking place in the wilderness. Informal education is self-directed learning available 

to all wilderness visitors. The realization of the “informal” component of the educational purpose can 

be considered as numerically congruent with the realization of the recreational purpose: All those who 

are recreating are in some way engaged in informal education. Directed, formal education is also a 

proper activity in wilderness and also realizes the educational purpose. Formal education presented by 

a qualified instructor can promote a deeper, more comprehensive understanding of wilderness related 

subjects. An allocation of 10% of capacity is necessary to ensure that there is sufficient opportunity for 

formal education and classes, including the making of educational films. Trips that realize the 

educational purpose also, by definition, also realize the recreational purpose and therefore educational 

trips in excess of 10% of capacity would be allowed in non-restricted zones to help realize the 

recreational purpose. 
APPENDIX L 

L-14 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

The percent of capacity allocated to formal education is small for a number of reasons: 

 The educational purpose is largely being realized through informal education 

 NPS Management Policies directs that “. . . the service will, to the extent practicable, afford 

visitors ample opportunity for inspiration, appreciation, and enjoyment through their own 

personalized experiences-without the formality of program or structure.”26

 Commercial educational use in restricted and weekend-restricted zones will displace non 

commercial use. Under the overall structure of the Wilderness Act, denial of access to non 

commercial visitors in favor of commercial visitors should be minimized. 

Classes offered by accredited schools for which students receive academic credit are not considered 

commercial and are not restricted by this allocation (see section 5). 

For restricted zones, and weekend restricted zones on weekends, formal education conducted by 

noncommercial entities such as the NPS, and accredited schools, colleges, and universities conducting 

classes for academic credit is also realizing the educational purpose, and will first be subtracted from 

that 10% of capacity. The remaining allocation, if any, will be available for commercial formal 

education in order to realize the educational purpose. 

3. Scenic Purpose 

All visitors are engaging in informal appreciation of wilderness scenery, as are individuals located 

outside of wilderness who are looking in from a road or other developed area. Formal appreciation of 

wilderness scenery, such as art and photography workshops, can foster a more structured 

understanding of scenery and is also necessary to realize a purpose of the Wilderness Act. An 

allocation of 5 % of capacity is necessary to ensure that there is sufficient opportunity for formal 

appreciation of wilderness scenery, including the making of films that focus on wilderness scenery. 

Trips that realize the Scenic purpose also, by definition, also realize the recreational purpose and 

therefore Scenic trips in excess of 5% of capacity would be allowed in non-restricted zones to help 

realize the recreational purpose. 

The percent of capacity allocated to formal appreciation of scenery is small for a number of reasons: 

 The scenic purpose is largely being realized through informal appreciation, both inside and 

outside of wilderness 

 Policy guidance, noted above, that directs that non-formal opportunities be “ample.” 

 Commercial scenic use in restricted and weekend-restricted zones will displace non 

commercial use. Under the overall structure of the Wilderness Act, denial of access to non 

commercial visitors in favor of commercial visitors should be minimized. 

Art and photography classes offered by accredited schools for course credit are not considered 

commercial and are not restricted by this allocation (see section 5). 

 

26 NPS Management Policies 2006 8.2
Determination of the Extent Necessary for Commercial Services in the 

Wilderness Segments of the Merced Wild and Scenic River Corridor 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS L-15 

B. Day Use 

The only significant day use in the Merced River Corridor is in the Little Yosemite Valley area. Nearly 

all of this day use is on the one mile section of the John Muir Trail from the top of Nevada Fall to 

where the trail leaves the corridor near the designated camping area. An analysis of commercial use 

from 2005-2009 shows that all commercial day use in the corridor was limited to hikes to Half Dome. 

That use has already been limited through an Extent Necessary Determination for the Half Dome 

Stewardship Plan. That plan limits commercial day use to a maximum of 30 people per day for trips 

that realize the educational purpose and 15 people per day for trips that realize the scenic purpose. 

Those limits are appropriate for realizing the educational scenic purposes of wilderness in the Merced 

River corridor while protecting other wilderness values. 

C. High Sierra Camps 

In 1984, when Congress designated the Yosemite Wilderness, it allowed the continuation of the High 

Sierra Camps as a non-conforming use and designated the immediate areas of the camps as potential 

wilderness additions. The only High Sierra Camp in the Merced River corridor is Merced Lake. 

The camps are a commercial operation and offer seasonal, rustic accommodations. Under the 

preferred alternative of the Draft Merced River Plan the Merced Lake High Sierra Camp will provide 

42 guest beds, offer full meal service to guests, and sell sundry items to both camp guests and other 

visitors. It is typically open from early July to early September. The National Park Service, in 

conjunction with the concessioner, conducts commercial educational “loop trips” to the High Sierra 

Camps and provides formal interpretative educational programs to both High Sierra Camp guests and 

backpackers from nearby campgrounds. 

The Merced Lake High Sierra Camp is a substantial commercial presence and affects the wilderness 

experience of visitors in the area, as do the visitors, employees, support personnel, and supply trips 

going to and from the camp. The nature of the camp, with a nonconforming level of development and 

services, means that the Merced Lake zone is highly commercialized compared to those zones that 

have only more traditional, conforming outfitter and guide services. To prevent further 

commercialization of this area, the Merced Lake zone will be managed as “restricted” during July and 

August when the camp is open, and the commercial formal education provided by the NPS-concession 

loop trips will be subtracted from the overnight use allocations for such use, as well as noncommercial 

educational use. 

D. Disabled Access 

NPS Management Policies states that the agency must “make available equal opportunities for people 

with disabilities in all programs and activities.”27 For some people who are mobility impaired, 

commercial stock services may provide the only reasonable way to access the wilderness. This Extent 

Necessary Determination only prohibits some types of commercial use in two wilderness management 

 

27 NPS Management Policies 6.4.10
APPENDIX L 

L-16 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

zones (there are 53 such zones in the entire wilderness; 8 in the Merced River corridor) for a part of 

the use season. Like persons without mobility impairments, mobility impaired visitors may not be able 

to gain access to their preferred destination as part of a commercial trip during the restricted period. 

However, Yosemite has many other areas where visitors can take stock-assisted trips. As such, there 

are “equal opportunities” for mobility impaired individuals to use commercial stock trips to visit the 

Yosemite Wilderness. 

E. Other Commercial Use Limits 

In order to honor the clearly expressed legislative intent in the Wilderness Act to limit 

commercialization of wilderness, and the legislative mandate to permit commercial use only to the 

extent necessary to realize the wilderness purposes, the following policies will be implemented: 

 In the Yosemite Wilderness, off-trail areas are managed to provide outstanding opportunities 

to enjoy solitude as well as a more pristine natural environment: Group size is limited to eight 

instead of fifteen to provide enhanced opportunities for solitude, and stock use is generally 

prohibited to prevent stock impacts in areas without the protection of properly designed and 

hardened trails. Off-trail areas in the Merced River Corridor zones of the Yosemite 

Wilderness will be commercial-free areas. No commercial use will be allowed more than 1⁄4 

mile from a maintained trail, authorized cross country stock route, or public access road (as 

shown on the latest version of U.S.G.S. topographic maps.) 

 Overnight commercial trips are limited to two per zone per night. There are three reasons for 

this limit. First, this limit is necessary to protect areas from impacts due to displacement from 

restricted and weekend restricted zones. Such displacement, if not properly managed, could 

result in undesirable physical impacts from grazing or from the creation of new campsites 

large enough to accommodate large commercial groups of 12-15 people, as well as the social 

impacts of increased numbers of large groups. Second, this limit will help to prevent “harmful 

spikes in use”28 and protect the wilderness character of areas to which commercial use may be 

displaced under the operation of this plan.29 If three or more large commercial groups are all 

displaced to the most desirable unrestricted zone, it could create crowding that detracts from 

the wilderness experience of noncommercial visitors sharing a zone with such groups.30 A 

limit of two commercial trips per day in unrestricted zones will prevent this from occurring. 

Third, this limit will prevent commercial groups from dominating any one area and therefore 

further the intent of the Wilderness Act. 

These limits apply in all zones at all times in addition to the other restrictions noted above. 

 

28 See High Sierra Hikers v. Blackwell, 390 F.3d 630 (9th Cir. 2004): High Sierra Hikers Association v. Weingardt, 521 F. 

Supp. 2d 1065 (2007) (holding invalidates the USFS commercial use needs assessment in part because it failed to 

control harmful spikes in use). 29 For a review of the research demonstrating that harms caused by new impacts to areas not previously impacted are 

more extensive than harms to previously impacted areas (the “impact curve”), see Hammitt, W. & Cole, D. (1998) 

Wildland Recreation: Ecology and Management, 2d ed., New York: John Wiley 30 Recent empirical research on visitor experience in the Yosemite Wilderness has documented a visitor preference not 

to encounter stock parties and large campsites. See Newman, P., Manning, R. E., Dennis, D. F., & McKonly. (2005). 

Informing carrying capacity decision making in Yosemite National Park, USA using stated choice modeling. Journal 

of Park and Recreation Administration, 23(1), 75-89. 
Determination of the Extent Necessary for Commercial Services in the 

Wilderness Segments of the Merced Wild and Scenic River Corridor 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS L-17 

PART 7: EXTENT NECESSARY CALCULATIONS FOR THE MERCED RIVER 

CORRIDOR 

The following is an application of the rules in Part 7 to the wilderness portions of the Merced River 

corridor. They apply only to the Merced River corridor, and do not apply to commercial use 

associated with the High Sierra Camps. The allocations are summarized in Table 1. Some trips may 

realize all three purposes. Such trips will be allocated according to the purpose allocation that is most 

favorable to the commercial service provider.31

A. Limits on all Commercial Use: 

 No camping or travel by commercial groups allowed more than 1⁄4 mile from a maintained trail 

or public access road. No camping allowed in the Mount Lyell zone (The entire zone is off 

trail.) No more than two overnight commercial groups per night per zone. 

 All commercial stock trips are limited to a 1:1.5 stock to person ratio. Accordingly, for every 

multiple of 3 persons (including employees), only two pack animals are allowed in addition to 

3 riding stock. See section 9 B. 

B. Limits on Commercial Trips that only Realize the Recreational Purpose: 

1. Overnight Use 

 Restricted zones (LYV, June, July and August only; Merced Lake, July and August only): No 

overnight commercial use allowed. 

 Weekend restricted zones (LYV, May and September only; Merced Lake, September only): 

Commercial use allowed on weekdays; but prohibited on weekends and holidays. (This means 

no overnight stays on Friday and Saturday nights or Sunday night before a Monday holiday. 

July 4th will only be treated as a holiday during years when the federal holiday forms a three 

day weekend. 

 Commercial trips allowed in the Washburn Lake, Clark Range, South Fork, Johnson Creek, 

and Chilnualna Creek zones all year. Commercial trips allowed in the LYV zone October 

through April and the Merced Lake zones October through June. 

 

31 Such trips are also favorably evaluated under the minimum requirements analysis described in section 9 below 

because they help to realize multiple purposes at a lower impact than would multiple trips. 
APPENDIX L 

L-18 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

TABLE 1. COMMERCIAL RESTRICTIONS SUMMARY

Overnight Use 

Other Zones Weekend Restricted Zones Restricted Zones 

For commercial 

groups that realize: 

 Washburn Lake, Clark 

Range, South Fork, 

Johnson Creek, and 

Chilnualna Creek 

 LYV zone October 

through April and the 

Merced Lake zones 

October through June 

 LYV, May and September 

only; Merced Lake, 

September only 

 LYV, June, July and 

August only; Merced 

Lake, July and August 

only 

Only the recreational 

purpose 

 No off-trail travel 

 1:1.5 stock to person ratio

 Two commercial groups 

per zone per night 

 No off-trail travel 

 1:1.5 stock to person ratio 

 Two commercial groups 

per zone per night 

Monday-Thursday nights. 

No overnight use on 

weekend and holiday 

nights. 

 No overnight use 

The recreational and 

educational purposes 

 No off-trail travel 

 1:1.5 stock to person ratio

 two commercial groups 

per zone per night 

 No off-trail travel 

 1:1.5 stock to person ratio 

 Two commercial groups 

per zone per night 

 Merced Lake zone: Limited 

to 44 weekend use nights 

per month. 

 LYV zone: Limited to 131 

weekend use nights per 

month. 

 No off-trail travel 

 Merced Lake zone: No 

commercial use 

allowed. 

 LYV zone: Limited to 

465 use nights per 

month. 

The recreational and 

scenic purposes 

 No off-trail travel 

 1:1.5 stock to person ratio

 Two commercial groups 

per zone per night 

 No off-trail travel 

 1:1.5 stock to person ratio 

 Two commercial groups 

per zone per night 

 Merced Lake zone: Limited 

to 22 weekend use nights 

per month. 

 LYV zone: Limited to 65 

weekend use nights per 

month. 

 No off-trail travel 

 Two commercial groups 

per zone per night 

 Merced Lake zone: 

Limited to 78 use nights 

per month. 

 LYV zone: Limited to 

233 use nights per 

month. 

Merced River Corridor Summary 

Month 

Zone 

South 

Fork 

Johnson 

Creek 

Chilnualna 

Creek 

Clark 

Range 

Washburn Lake Mount 

Lyell 

Merced 

Lake 

LYV 

May No 

Camping 

Weekend 

Restricted 

June No 

camping 

Restricted 

July No 

camping 

Restricted Restricted 

August No 

camping 

Restricted Restricted 

September No 

camping 

Weekend 

Restricted 

Weekend 

Restricted 
Determination of the Extent Necessary for Commercial Services in the 

Wilderness Segments of the Merced Wild and Scenic River Corridor 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS L-19 

C. Limits on Commercial Trips that Realize the Recreational and Educational 

Purposes: 

1. Overnight Use 

 Restricted zones (LYV, June, July and August only; Merced Lake, July and August only): 

Merced Lake zone: Commercial use prohibited because commercial education associated with 

the High Sierra Camp Loop Trips conducted by the National Park Service exceeds 10% of 

capacity, which makes it unnecessary to allocate additional capacity for commercial use in 

support of the educational purpose on this trail corridor. LYV zone: A negligible amount of 

noncommercial formal education is occurring. Commercial use limited to 465 use nights per 

month.32

 Weekend restricted zones (LYV, May and September only; Merced Lake, September only): 

Commercial use allowed on weekdays. For weekends and holidays (as defined above) 

commercial use limited to 131 weekend use nights per month in the LYV zone33 and 44 

weekend use nights per month in the Merced Lake zone.34 Commercial use allowed on 

weekdays. 

 Commercial trips allowed in the Washburn Lake, Clark Range, South Fork, Johnson Creek, 

and Chilnualna Creek zones all year. Commercial trips allowed in the LYV zone October 

through April and the Merced Lake zones October through June. 

D. Limits on Commercial Trips that Realize the Recreational and Scenic 

Purposes: 

1. Overnight Use 

 Restricted zones (LYV, June, July and August only; Merced Lake, July and August only): 

Merced Lake zone: A negligible amount of noncommercial, formal scenic use is occurring. Use 

limited to 78 use nights per month.35 LYV zone: A negligible amount of noncommercial scenic 

use is occurring. Commercial use limited to 233 use nights per month.36

 

32 Calculated as follows: Capacity for LYV is 150 people per night. 150 x 31 (number of nights/month) equals 4650 use 

nights. 10% of 4650 equals 465 use nights. Average noncommercial educational use nights (college classes, etc), 

average, 2009-2010 is 0 use nights. 465 minus 0 equals 465 use nights available for commercial education. 

33 Calculated as follows: Capacity for LYV is 150 people per night. 150 x 8.7 (average number of weekend nights/month) 

equals1305 use nights. 10% of 1305 equals 131 use nights. Average noncommercial educational use nights (college 

classes, etc), average, 2009-2010 is 0 use nights. 131 minus 0 equals 131 use nights available for commercial formal 

education. 

34 Calculated as follows: Capacity for Merced Lake is 50 people per night. 50 x 8.7 (average number of weekend 

nights/month) equals 435 use nights. 10% of 435 equals 44 use nights. Average noncommercial educational use nights 

(college classes, etc), average, 2009-2010 is 0 use nights. 44 minus 0 equals 44 use nights available for commercial 

formal education. 

35 Calculated as follows: Capacity for Merced Lake is 50 people per night. 50 x 31 nights per month equals 1550 use 

nights. 5% of 1550 equals 78 use nights. Average noncommercial scenic use nights (college classes, etc), average, 2009-

2010 is 0 use nights. 78 minus 0 equals 78 use nights available for commercial scenic use. 36 Calculated as follows: Capacity for LYV is 150 people per night. 150 x 31 nights per month equals 4650 use nights. 5% 

of 4650 equals 233 use nights. Average noncommercial scenic use nights (college classes, etc), average, 2009-2010 is 0 

use nights. 233 minus 0 equals 233 use nights available for commercial scenic use. 
APPENDIX L 

L-20 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

 Weekend restricted zones (LYV, May and September only; Merced Lake, September only): 

Commercial use allowed on weekdays. For weekends and holidays (as defined above), 

commercial use limited to 65 use nights per month in the LYV zone37 and 22 use nights per 

month in the Merced Lake zone.38

 Commercial trips allowed in the Washburn Lake, Clark Range, South Fork, Johnson Creek, 

and Chilnualna Creek zones all year. Commercial trips allowed in the LYV zone October 

through April and the Merced Lake zones October through June. 

PART 8: THE COMMERCIAL USE APPLICATION PROCESS 

A. Procedures Applicable to All Commercial Services in Wilderness 

Implementation of this Extent Necessary Determination will be integrated into Yosemite’s CUA and 

SUP application procedures and concession management operations. All entities, including 

concessioners CUA holders, and SUP holders desiring to provide commercial services in the 

designated wilderness of the Merced River corridor shall do the following: 

(1) The concessioner, CUA, or Special Use Permit holder must submit a proposed trip itinerary to 

the Yosemite Wilderness Office by May 1 or as soon as is feasible. The itinerary must be 

received prior to any trip entry into the park. The itinerary must provide a schedule of planned 

trips. For overnight trips, the itinerary must include the dates, point of entry and exit, each 

night’s camping location, and the group size (including employees). Day trips must include the 

date, group size, trailhead, and destination. Itineraries received prior to May 1 will be used to 

assign trips for the summer season and may include a second and third choice of trips. 

(2) For educational and scenic trips, the applicant must submit an explanation of the manner in 

which the proposed commercial trip meets the educational or scenic purposes, along with 

copies of, or internet links to, all advertising and other promotional materials related to that 

trip and submit educational syllabus for trip and documentation showing that employees are 

trained and qualified to provide such education. 

B. The Minimum Requirement Concept 

By policy, the National Park Service must apply the minimum requirement concept to decisions about 

commercial use in wilderness.39 The minimum requirement concept is a two part process that 

determines “if administrative actions, projects, or programs undertaken by the Service or its agent and 

affecting wilderness character, resources, or the visitor experience are necessary, and, if so how to 

minimize impacts.”40

 

37 Calculated as follows: Capacity for LYV is 150 people per night. 150 x 8.7 (average number of weekend nights/month) 

equals1305 use nights. 5% of 1305 equals 65 use nights. Average noncommercial scenic use nights, average, 2009-2010 

is 0 use nights. 65 minus 0 equals 65 use nights available for commercial scenic use. 38 Calculated as follows: Capacity for Merced Lake is 50 people per night. 50 x 8.7 (average number of weekend 

nights/month) equals 435 use nights. 5% of 435 equals 22 use nights. Average noncommercial scenic use nights, 

average, 2009-2010 is 0 use nights. 22 minus 0 equals 22 use nights available for commercial scenic use. 

39 NPS Management Policies 2006 6.4.4 40 NPS Management Policies 2006 6.3.5 
Determination of the Extent Necessary for Commercial Services in the 

Wilderness Segments of the Merced Wild and Scenic River Corridor 

Merced Wild and Scenic River Comprehensive Management Plan / DEIS L-21 

As part of the minimum requirement process, the National Park Service weighs the impacts and 

benefits to wilderness character. Commercial trips that realize more than one purpose accrue more 

benefit to wilderness character than those that only realize one purpose but have the same amount of 

impact. For this reason trips that realize a higher number of purposes will receive preference over 

those realizing a lower number of purposes when allocating access. 

Part of a minimum requirement decision is determining whether an activity is wilderness dependent. 

Wilderness dependence as used here means if the activity can occur outside of wilderness with little 

loss of value, it should not take place in wilderness. The wilderness dependence criteria will be used 

during the application screening process. Commercial trips whose primary purpose is teaching a 

subject that is not wilderness dependent will be treated as recreational rather than educational. 

Examples of such topics are weight loss and cooking. 

Consistent with this concept, when two commercial groups that are realizing the same number of 

purposes are competing for the same date in the same location, the lower impact trip will be given 

preference. When comparing otherwise equivalent commercial stock trips preference will be given to 

the trip with the lower stock-to-client ratio. 

In order to minimize the impacts of commercial stock use, all commercial stock trips are limited to a 

1:1.5 stock to person ratio. Accordingly, for every multiple of 3 persons (including employees), only 

two pack animals are allowed in addition to 3 riding stock. 

C. Process for Allocating Proposed Trips 

In the event that there is more than one entity that desires to provide Commercial Services on the same 

date in the same zone, priority shall be determined by the application of the following steps, in order: 

(1) Each proposed commercial trip shall be awarded one (1) point for each wilderness public 

purpose (i.e., recreational, educational, scenic) that it realizes. Priority shall be granted to 

proposed trips with higher point totals; 

(2) Proposed commercial trips that utilize a lower-impact mode of transportation will be given 

priority over those using higher impact modes of transportation; and 

(3) In the case of otherwise comparable stock trips, the trip with the lowest stock to client ratio 

will be given priority. 

(4) Any remaining conflicting proposed commercial trips after the application of steps (1) through 

(3) above will be resolved through a lottery for proposed commercial trips that will be 

conducted on May 1 of each calendar year. 

All trips proposed after the May 1 lottery will be allocated on a first come first served basis. With 

respect to trips requested on the same date, any conflicts over requested dates and trailheads will be 

resolved by the application of steps (1) through (4) above. 
APPENDIX L 

L-22 Merced Wild and Scenic River Comprehensive Management Plan / DEIS

D. Compliance 

Wilderness Rangers routinely check on Commercial Trips in the field to assure compliance with park 

regulations. An assessment of the extent to which a Commercial Service provider has met its objective 

with respect to satisfaction of wilderness purposes will be added to the CUA contact form, for example 

to evaluate the claim that wilderness education is being provided by qualified personnel in addition to 

recreation. 

Failing to provide promised educational or scenic opportunities may be grounds for limiting a 

commercial service provider’s ability to provide future commercial trips in the Yosemite Wilderness. 

PART 9: THE REASSESSMENT PROCESS 

The limits on commercial use imposed by this plan will be recalculated when significant changes in use 

patterns occur. Two current actions may affect this process. The first is research on wilderness travel 

patterns that was completed in 2010. Trailhead quotas will be adjusted based on the results of this 

study. As a result, travel patterns may change in a way that would affect the results of an Extent 

Necessary Determination. In addition, the National Park Service has taken the initial steps of rewriting 

the Yosemite Wilderness Stewardship Plan which will include an Extent Necessary Determination for 

the entire wilderness. At that time both visitor use patterns and the Extent Necessary methodology will 

be reevaluated.