Two Short Travel Surveys

National Park Service
U.S. Department of the Interior
Social Science Program

Expedited Approval for NPS- Sponsored Public Surveys
1.

Project Title ⎢
Submission Date:

2.

Abstract:

Yosemite Wilderness Visitor Travel Patterns

May 6, 2009

The purpose of this study is to collect travel route information and campsite locations from
wilderness visitors in Yosemite National Park in order to: 1) understand changes in travel
patterns in the park’s wilderness, and 2) create a computer travel simulation model to inform
park managers about wilderness zone capacity issues and decisions about trailhead quotas.
(not to exceed 150 words)

3.

Principal Investigator Contact Information
First Name:
Title:
Affiliation:
Street Address:
City:

4.

Last Name:

Steven

Martin

Professor
Humboldt State University
1 Harpst Street
Arcata

State:

Phone:

707 826 5637

Fax:

Email:

[email protected]

CA

Zip code:

95521

707 826 4145

Park or Program Liaison Contact Information
First Name:

Last Name:

Bret

Title:

Branch Chief, Visitor Use/Social Sciences

Park:

YOSE

Park
Office/Division:
Street Address:
City:

Meldrum

Resources Management & Science

5083 Foresta Rd, RMS Bldg.
El Portal

Phone:

209 379 1216

Email:

[email protected]

State:
Fax:

CA

Zip code:

209 379 1131

95318

Project Information
5.

Park(s) For Which Research
is to be Conducted:

6.

Survey Dates:

7.

Type of Information Collection Instrument (Check ALL that Apply)

8.

‰

Mail- Back
Questionnaire

‰

Other (explain)

Survey Justification:
(Use as much space as
needed; if necessary include
additional explanation on a
separate page.)

Yosemite National Park

5/1/2010

(mm/dd/yyyy)

X On- Site
Questionnaire

to

X Face- to- Face
Interview

9/30/2010

‰

(mm/dd/yyyy)

Telephone
Survey

‰

Focus
Groups

Social science research in support of park planning and management is mandated
in the NPS Management Policies 2006 (Section 8.11.1, “Social Science Studies”).
The NPS pursues a policy that facilitates social science studies in support of the
NPS mission to protect resources and enhance the enjoyment of present and future
generations (National Park Service Act of 1916, 38 Stat 535, 16 USC 1, et seq.).
NPS policy mandates that social science research will be used to provide an
understanding of park visitors, the non-visiting public, gateway communities and
regions, and human interactions with park resources. Such studies are needed to
provide a scientific basis for park planning, development, operations,
management, education, and interpretive activities.
The last time information on wilderness use in Yosemite was collected
systematically was in the 1970s, when the original wilderness travel use simulator
was created and trailhead quotas determined. Park managers suspect travel
patterns have changed, and that some wilderness travel zones could be
experiencing levels of overnight use that exceed their capacity. If true, trailhead
quotas would need to be adjusted accordingly. This study will provide the
information to allow managers to make informed decisions about adjusting
trailhead quotas.
Literature Review: The Yosemite Wilderness experienced heavy use in the late
1960s and early 1970s with visitor nights peaking in 1975 at 218,890 and
averaging 172,310 visitor nights from 1972 to 1979 (Van Wagtendonk 1981).
During that time, the park determined an overnight user capacity for each of the
wilderness travel zones, loosely corresponding geographically to watershed
drainages and based on zone acreage, trail mileage, and ecological fragility. A
Wilderness Use Simulation Model was created and used to derive trailhead quotas
based on data that related overnight zone use to trailhead entries (Van
Wagtendonk 1986).
Using the trailhead quota system and limiting the number of visitors who start at a
given trailhead each day presumably maintains overnight use in each of the travel
zones at or below capacity. This is valid as long as: 1) patterns of visitor use
remain roughly the same as when the trailhead quotas were established, and 2)
visitors adhere to the planned itinerary recorded on their permits. Current permit
data suggest strongly that patterns of visitor use have changed since the original
Wilderness Use Simulation Model was created and the trailhead quotas were
derived. In addition, previous research on Yosemite National Park permit validity
revealed that 62 percent of all parties with permits made changes to their trips
(Van Wagtendonk and Benedict 1980). For all of these reasons, trip duration, the
zones in which nights are spent, and exit trailheads may differ between permitted
and actual itineraries.
The data on which the original trailhead quotas were based, and the data relating
intended and actual routes, are now over 30 years old. The supposition is that

visitor travel patterns have become shorter in distance and duration. As a result,
the overnight capacities of the travel zones nearest to trailheads may be being
exceeded. An accurate account of Yosemite wilderness zone use and itinerary
modification will recalibrate the current trailhead quotas to better manage the
travel zones for optimal biophysical and social conditions. The NPS will use
Extend modeling software to model overnight visitor use. This modeling software
has been employed previously and successfully in both Yosemite National Park
and other wilderness settings (Lawson et al., 2008; Lawson et al., 2006).
We propose to survey a random sample of permitted wilderness groups to obtain
their actual trip characteristics, which we will then compare with their intended
characteristics. This comparison will allow us to calibrate the permit data to
reflect actual behavior, thereby allowing more accurate modeling of important
wilderness use parameters (e.g., van Wagtendonk and Benedict, 1980).
9.

Survey Methodology: (Use
as much space as needed; if
necessary include
additional explanation on a
separate page.)

(a) Respondent universe: One person 18 years of age or older from each party
that spends at least one night in a wilderness zone in Yosemite National Park
between May 1 and September 30, 2010, except those staying overnight in
High Sierra Camp lodging. (The High Sierra Camps are backcountry tent
cabins managed by the park’s concessioner, Delaware North Parks and
Resorts. Their capacity is determined by the number of available beds in each
cabin.)
(b) Sampling plan/procedures: Each overnight wilderness party must obtain a
permit by physically visiting one of the Wilderness Centers in Yosemite or a
cooperative Forest Service permit issuing station (if their trip originates on
adjacent Forest Service land). These permits record attributes of wilderness
use, such as party size, trip dates, entrance trailhead, wilderness zones in
which nights are spent, and exit trailhead. Assuming that all groups entering
the wilderness obtain a permit as required, the permit data provide an
accurate estimate of the total number of groups using the wilderness.
Selecting an appropriate sample size requires balancing resources available to
conduct sampling and data analysis against meeting the objectives of the
study (Manly, 2001). In addition, because the data collection requires time
on the part of Yosemite National Park personnel and visitors, we sought to
minimize the sample size, both to limit the amount of time required to
administer and complete the survey and to minimize deviation from sampling
protocols that could occur due to extra workload required of Park personnel
on selected sampling days. Based on itineraries from wilderness permits
issued in 2009, on deviations from intended itineraries observed by van
Wagtendonk and Benedict (1980), and on properties of standard statistical
estimators and tests (Manly 2001), we determined that sampling 10% of all
wilderness parties will meet the objectives for sample size (see section d
below for more detail on sample sizes).
In 2009, 12,276 wilderness permits were issued in Yosemite. Allowing for a
potential 5% increase in use, we estimate that 13,000 visitors will obtain
wilderness permits in 2010. Assuming a 60% response rate (see Section (d)),
a desired 10% sample size (n = 1,300) will require distributing 2,167 survey
instruments.
Previous studies (van Wagtendonk, 1981) and the 2009 permit data show that
wilderness use in Yosemite is not distributed uniformly through the season.
Use is much higher on weekends/holidays than on weekdays and increases
gradually from the beginning of the season to reach a peak around early
August, after which there is a rapid decline to essentially zero use by the end
of September. The most efficient sampling scheme will allocate sampling
probabilities according to temporal distribution of use. The sampling frame

will consist of all weekends (Friday and Saturday nights for regular
weekends, Friday through Sunday nights for three-day holiday weekends)
and all weekdays in the study period. The sample will first be divided into
two strata: 1) all weekends, and 2) the remaining weekdays. Each stratum
will be sampled in proportion to the proportion of total visitor-nights in that
stratum, according to the 2009 permit data. Within each stratum, the
probability of a given wilderness zone unit being selected for sampling will
be equal to the proportion of total visitor-nights in that stratum accounted for
by trips that began in that unit. These proportions will again be taken from
the 2009 permit data. The number of units selected for sampling will be equal
to that necessary to distribute the desired 2,167 survey instruments.
To account for the possibility that temporal distribution of use is not uniform
across wilderness zones, we will use Monte Carlo simulation to assess
whether the sampling scheme will result in samples that are unbiased with
respect to use of wilderness zones. We will generate 2,000 possible samples
under the above sampling scheme and assess whether the probability of
sampling parties using each zone is approximately proportional to the
distribution of use across zones. If not, the sampling scheme will be further
refined to result in a sampling scheme that allocates sampling effort in
proportion to both temporal and spatial distribution of visitor-nights.
(c) Instrument administration: If a given weekend is selected for sampling, we
will distribute survey instruments to all parties that obtain their permit
between Thursday afternoon and Saturday morning. On sampled weekdays,
we will distribute survey instruments to all parties that obtain their permit
during the afternoon of the previous day and the morning of the selected day.
At the time the permit is issued, the issuing ranger will request intended
campsite locations from the party and an e-mail address. This will be
recorded as part of the permit procedure. Each party will then be given a map
of the wilderness (just the portion appropriate to their route) showing trails
and dominant landscape features and be asked to trace their route and mark
their campsites. The map includes two questions about trip behavior on the
back. Because the information requested is for the entire party, rather than a
single individual, sampled groups will be told that the route map and
questions can be completed by any individual over the age of 18 in the party.
The issuing ranger will record a unique identifying number on this map so
that it can be connected back to the permit data. Once the trip is completed,
the party will return the map to the park, either by putting it inside their rental
food canister, dropping it off in person at a Wilderness Center, or handing it
back to the entrance station ranger as they exit the park (all vehicles exiting
the park must stop at the entrance station).
A reminder e-mail will be sent to all survey participants who do not return a
map within a week of the scheduled end of their trip. A second e-mail will be
sent one week following the first one to all persons who have not yet returned
a map.
NPS employees and volunteers who staff the Wilderness Centers will
distribute the maps and instructions to visitors. To assure quality control over
the sampling protocol, the PI will meet with staff before the study begins to
train them in the survey methods. An instruction sheet will be developed that
can be referred to if any questions arise. In addition, the PI will meet again
with staff after the first week or two of sampling to review procedures and
discuss any unanticipated issues. A graduate research assistant will be present
in the park for the duration of the study and also will be able to answer
questions. Finally, the PI will visit the park periodically and during these
visits, he will check with the staff to monitor progress. Social science staff in
the park also will be available to answer questions about the survey protocol.

(d) Expected response rate/confidence levels: The response rate is expected to be
approximately 60%. The questionnaire is very short and simple, with only
two questions to answer, along with a route to be traced on a map. The study
conducted by van Wagtendonk and Benedict (1980) in Yosemite in the 1970s
obtained a response rate of over 90%. However, more recent research
indicates that the propensity to respond may be declining. Newman and
Manning (2002) collected route data from overnight wilderness visitors in
2001and obtained a response rate of 45%. We expect our response rate to be
higher, because their study included a lengthy and detailed questionnaire, in
addition to the map. Also, because 60% of Yosemite overnight wilderness
visitors whose trips originate in the park now rent food canisters as a
protection against bears, it will be very easy for them to place their completed
map in their empty food canisters when they are returned. The e-mail
reminders will encourage additional responses. For all of these reasons, we
expect a higher return rate than reported by Newman and Manning, but lower
than the early study by van Wagtendonk and Benedict.
Using the standard deviation in mean trip duration calculated from the 2009
permits, a sample size of 1,300 yields a standard error on the estimate of
mean trip duration of 0.157 nights. Thus, at 95% confidence, the sampling
error is 0.308 nights. The mean trip duration calculated from the 2009 permit
data was 4.40. Van Wagtendonk and Benedict (1980) reported that actual trip
duration was 0.5 nights less than intended trip duration. If that deviation
holds in our population, the expected trip duration will be 3.90 (4.40 – 0.5),
so the relative sampling error, at 95% confidence, is 0.308/3.90 = 7.9%.
Looked at another way, we will be able to detect, at the 95% confidence
level, deviations in mean trip duration of 0.308 nights.
Van Wagtendonk and Benedict (1980) also reported that about 60% of parties
altered their trip in either duration or location relative to the trip itinerary they
entered on their wilderness permit. With a sample size of 1,300, the standard
error in estimating a proportion of 0.6 is 0.0129, so at 95% confidence, the
sampling error is 0.0253. Thus, the relative sampling error, at 95%
confidence, is 0.0253/0.6 = 4.2%.
Based on the 2009 permit data (intended itineraries), the highest frequency
with which a wilderness zone exceeded capacity was 38 nights out of the
year. Some 953 parties intended to spend at least one night in this particular
zone, accounting for 5.7% of total visitor-nights in 2009. With a sample of
1,300, and with selection probability proportional to use, we expect a sample
size of 74 parties spending at least one night in this specific zone. Based on
the standard deviation of trip length for parties intending to use this zone in
2009, the resulting standard error for the estimate of mean trip duration is
0.077. Thus, at 95% confidence, the sampling error is 0.15, indicating that
we will be able to detect a deviation in mean trip length to this zone of 0.15
nights. The mean intended duration of visits to this zone in 2009 was 1.43, so
we will be able to detect a deviation of about 0.15/1.43 = 10.5%.
(e) Strategies for dealing with potential non-response bias: Respondents will be
compared to non-respondents on several available characteristics recorded on
the permits completed by all parties sampled. These include intended
campsite, state or country of residence, day of week, month, party size, and
trip length. The implications of any non-response bias for interpretation of the
findings will be discussed in the final technical report.
(f) Description of any pre-testing and peer review of the methods and/or
instrument (recommended): The instrument is similar to those used in
previous studies of wilderness campers and day hikers. In addition, the

questions have been reviewed by the Social Science Branch in Yosemite NP.

10.

13.

Total Number of
Initial Contacts |
Expected Respondents:

2167

1300

11.

Estimated Time
to Complete
Initial Contact |
Instrument
(mins.):

2

5

12.

Total
Burden
Hours:

181

Reporting Plan: Survey results will be compiled, analyzed and presented in a technical report that
will be submitted to NPS officials in Yosemite National Park. Analysis will
include A copy of the report will be sent to the NPS Social Science Division to be
archived in the Social Science Studies Collection.
References
Manly. 2001. Statistics for Environmental Science and Management. Chapman
and Hall/CRC, Boca Raton, FL.
Lawson, Itami, Gimblett and Manning. 2006. Benefits and challenges of computer
simulation modeling of backcountry recreation use in the Desolation Lake area of
the John Muir wilderness. Journal of Leisure Research 38(2):187-207.
Lawson, Kiser, Hockett, Reigner, Chamberlin and Choi. 2008. Visitor use
computer simulation modeling to address transportation planning and user
capacity management in Yosemite Valley, Yosemite National Park. Final
Research Report submitted to the National Park Service.
Newman and Manning. 2002. Integrating social, ecological and managerial
indicators of quality into carrying capacity decision-making in Yosemite National
Park Wilderness. Final research report submitted to NPS.
Van Wagtendonk, J. 1981. The effect of use limits on backcountry visitation
trends in Yosemite National Park. Leisure Sciences 4:311-323.
Van Wagtendonk, J. 1986. The determination of carrying capacities for the
Yosemite Wilderness. USDA Forest Service general technical report INTVan Wagtendonk, J. and J. M. Benedict. 1980. Wilderness permit compliance
and validity. Journal of Forestry 78:399-401.
Quality Assurance for Yosemite National Park Visitor Survey
Steven Martin, Principal Investigator, Humboldt State University
Bret Meldrum, Branch Chief, Visitor Use and Social Sciences, Yosemite National
Park.
The staff of Yosemite National Park is committed to the success of a visitor
survey which will provide valid scientific results for future park planning. Quality
assurance in the field will be provided by the onsite park coordinator and/or his
designee, who will oversee the survey and assist the P.I. in training the staff of
permanent and seasonal park employees and volunteers. This staff will carry out
the distribution of the overnight surveys. Additional oversight will be provided by
Yosemite’s management staff (Mark Fincher, Ken Watson, Paul Gallez).
Responsibilities of Park Coordinator
• Oversees the survey onsite to ensure a valid, non-biased sampling.
• Assists the P.I. in training all employees who will be distributing surveys on the
survey process before the survey begins, and train all new employees who will be

distributing surveys as the survey continues through the season.
• Ensures ample visitor center staffing on the pre-determined survey days so that
those employees responsible for distributing surveys will not be
diverted away from this priority to fulfill other duties.
• Makes all other staff members aware of the survey so that they may answer
survey-related questions upon encountering participants in the
park.
• Positions survey drop boxes so that they are highly visible and easily accessible.
• Discuss collection protocols with visitor center staff.
Responsibilities of Surveyors (Permanent and seasonal employees/volunteers)
• Will be trained according to the pre-determined survey distribution instructions
and guidelines prior to distributing surveys.
• Will be dedicated to that duty for the survey day.
• Will adhere to survey distribution instructions to ensure valid, accurate results.
• Will maintain survey logs recording any refusals and the observable
characteristics of those refusers for use in a non-response bias analysis.
Responsibilities of Principal Investigator
• Prepares a detailed sampling protocol document to use in training park staff and
to guide and remind interviewers of the protocol.
• Conducts at least one training session in collaboration with the Park Survey
Coordinator at the beginning of the survey season (the beginning of the survey
season will generally coincide with the start date of summer seasonal employees).
• Ensures a graduate student will be onsite for the duration of the study to collect
surveys and be in contact with park staff.
• Is in continuous contact with graduate student and park staff conducting the
survey.
• Makes park visits as needed to ensure continued commitment.
• Provide reports as specified in the agreement.

Verbal script for initial contact (this will be embedded into the larger wilderness permit process as
carried out by the NPS permit-issuing ranger):
You’ve told us where you intend to camp, but we know that sometimes people’s plans change once they
get out there, and that’s okay. So we’d like to give you a map that covers the area where you’ll be hiking
and camping, and ask you to trace your actual hiking route with a solid line, and mark the location of each
of your campsites with a circled number corresponding to the night of your trip. If you’re carrying a GPS
you can even provide the coordinates of your campsites if you wish, but that’s up to you. There are also
two simple questions on the back of the map we’d ask you to answer. You are not required to complete
the map or answer these questions, but the information you provide will help us in managing Yosemite..
When you exit the wilderness, you can return the map by leaving it inside your rental food storage
canister, or by dropping it in the marked box outside the Wilderness Center closest to where you exit, or
by handing it to an Entrance Station ranger when you leave the park. Please be sure to trace your route
and number your campsites and return the map to us. This type of data hasn’t been collected from
Yosemite visitors for 30 years, and the park desperately needs to update its information on people’s
hiking routes and campsite locations.
Additional Information Provided upon Request.
16 U.S.C. 1a-7 authorizes collection of this information. This information will be used by park managers
to better serve the public. Response to this request is voluntary. No action may be taken against you for
refusing to supply the information requested. An agency may not conduct or sponsor, and a person is not
required to respond to, a collection of information unless it displays a currently valid OMB control
number.
BURDEN ESTIMATE STATEMENT: Public reporting burden for this form is estimated to average 5
minutes per response. Direct comments regarding the burden estimate or any other aspect of this form to:
Bret Meldrum, Branch Chief
Visitor Use/Social Science
Yosemite National Park
5083 Foresta Rd, RMS Bldg.
El Portal, CA 95318
(209) 379-1216
[email protected]

Visitor Use Map

Sunrise Lakes/Clouds Rest trailhead

Legend
Trails
Trailheads
Roads

"

0

0.25

0.5
Miles

1

Visitor ID _________
Trip ID ___________

OMB # xxxx-xxxx (NPS # xx-xxx)
Expiration Date: xx/xx/xxxx 

We know that sometimes people’s plans change once they get out into the wilderness. That’s okay. But park managers
need accurate information on people’s camping locations. This type of data hasn’t been collected from Yosemite visitors
for 30 years. The park needs to update its data on people’s hiking routes and campsite locations in order to know where
crowding or camping impacts might occur.
On the map on the reverse side, we’d like you to please trace your hiking route with a solid line, and mark the location of
each of your campsites with a circled number corresponding to the night of your trip. If you’re carrying a GPS you can
even provide the coordinates of your campsites if you wish, but that’s up to you.
We only need you to trace your camp-to-camp route. You don’t need to mark the route of any day hikes or side trips you
may take. Please remember to mark each of your campsites with a circled number corresponding to the night of your trip.
When you exit the wilderness, you can return the map by leaving it in your rental food storage canister (if you have one),
or by dropping it in the marked box outside the Wilderness Center closest to where you exit, or by handing it to an
Entrance Station ranger when you leave the park. Please be sure to trace your route and number each of your
campsites and return the map to us. This information will help park managers protect the Yosemite Wilderness. Please
also answer the two questions below, and thank you for your assistance and cooperation!
On this trip in the Yosemite wilderness, which of the following activities did you or your group participate in? Please
check (√) all that apply. [3. ACT18]
Climbing
Fishing
Other (Please specify) ________________________________________________________________
While in Yosemite National Park before and after the backpacking portion of your visit, which of the following
activities did you or your group participate in? Please check (√) all that apply. [3. variation ACT18]
Take a scenic drive
View roadside exhibits
Day hike
Visit visitor center
Eat in park restaurant
Stay in park lodging
Camp in developed campground
Other (please specify)

PRIVACY ACT and PAPERWORK REDUCTION ACT statement: 16 U.S.C. 1a-7 authorizes collection of this
information. This information will be used by park managers to better serve the public. Response to this request is voluntary. No
action may be taken against you for refusing to supply the information requested. An agency may not conduct or sponsor, and a
person is not required to respond to, a collection of information unless it displays a currently valid OMB control number.
BURDEN ESTIMATE statement: Public reporting burden for this form is estimated to average 5 minutes per response. Direct
comments regarding the burden estimate or any other aspect of this form to: Bret Meldrum, Yosemite National Park, 5083
Foresta Rd, RMS Bldg., El Portal, CA 95318, (209) 379-1216, [email protected]

YOSEMITE WILDERNESS VISITOR STUDY, E-MAIL FOLLOW-UPS
Script for e-mail reminder:
[date and trailhead of trip included in subject line]
Hello overnight Yosemite wilderness visitor. Earlier this summer you took a camping trip
into the Yosemite Park wilderness. When you picked up your permit at the park’s
Wilderness Center, you were given a map and asked to trace your route and mark/number
your campsites. If you have already returned this map to us, thank you. If you have not,
please mail it today with your hiking route and numbered campsite locations to Dr.
Steven R. Martin, ENRS Dept., Humboldt State University, 1 Harpst Street, Arcata, CA
95521. This information will help park managers better manage the park’s wilderness.
If you no longer have the map, we’d be happy to send you a replacement. To request a
replacement map, please e-mail us at [email protected] and tell us which trail or
trailhead you used, and we’ll send the correct map to you. (You can also make it a lot
easier for us by providing your mailing address, so we don’t have to look it up from your
permit!) You can return the map by mailing it to Dr. Steven R. Martin, ENRS Dept.,
Humboldt State University, 1 Harpst Street, Arcata, CA 95521.
Second e-mail follow-up:
Hello, I’m e-mailing you about the survey of Yosemite wilderness users that you agreed
to participate in this summer. The waiting period for incoming maps is almost over, and
we have not yet received yours. I would appreciate you completing another one unless
you mailed it within the past few days.
The staff of Yosemite National Park is anxiously awaiting the survey results. They want
to use the information you provide to better manage the park’s wilderness and provide
enjoyable visitor experiences. I urge you to complete the map and questionnaire and
return it by (month day). Your contribution to the success of this study is greatly
appreciated.
Please mail your map with your hiking route and numbered campsite locations to Dr.
Steven R. Martin, ENRS Dept., Humboldt State University, 1 Harpst Street, Arcata, CA
95521.
Should you have questions, or if you need a replacement map, please contact me at
[email protected].
Thank you!