Preventive success! Grand Canyon’s response to search-and-rescue overload

By C. J. Malcolm and Hannah Heinrich

There was no doubt in anyone’s mind that search-and-rescue events (SARs) were skyrocketing in the 1990s at Grand Canyon National Park (fig. 1). In a 13-year span from 1983 to 1996, SARs doubled. The critical tipping point for this dangerous trend occurred in summer 1996. That year, the park set records for search and rescues that remain in place to this day. Five heat-related deaths, 300 heat-related search-and-rescue incidents, and 482 total SARs devastated families and stressed responding rangers to their limits. On average, SARs during the late 1990s at Grand Canyon National Park cost taxpayers $1 million per year (Malcolm and Heinrich 2012). Something needed to change.

Trends in the number of park SARs at Grand Canyon, 1983–2014. SARs were on the rise until 1996, reaching a high of approximately 480 that year. In 1997 the trend began to decline under PSAR and by 2014 the trend line had declined to approximately 275 SARs
Figure 1. The graph details the number of search and rescues at Grand Canyon National Park from 1983 to 2014. Trends diverge after 1996, the year the park implemented the Preventive Search and Rescue Program.

Ken Phillips, retired branch chief of Search and Rescue for the National Park Service and chief of Emergency Services at Grand Canyon National Park, recounts the experiences of a Grand Canyon ranger during these challenging years.

In the summer months, the hottest months, we were totally in a reactionary mode and everything was based off the South Rim—unless a call was close to Indian Garden or Phantom Ranch. As soon as SAR Shift or back then, “SAR On-Call,” … would receive a hiker-in-distress call, they would start looking around for someone to send down the trail. This happened every day, day in and day out; and if you have a couple of those calls a day, which we did, you start burning people out. You’re just running out of resources to do that. For our responding rescuers the cumulative fatigue factor was insane because you have got to rush down there; these were vague reports, “Somebody collapsed on the trail …” Well is that a cardiac arrest or is that somebody just sitting in the shade? We didn’t know. But you can’t delay your response. Oftentimes it involved running down the trail. So imagine how fast you’d chew up responders running down the trail at the hottest time of the year. You get down there and you’re sweating all over the patient, you’re tied up on this call, and you’re spent for the rest of the day. That’s how the normal process went down before we were able to pre-deploy, before PSAR … This took an unbelievable toll on the staff.

After a decade of reactionary responses and the exigent year of 1996, rangers were exhausted and disheartened. The constant summertime requests for assistance created an environment of rescuer fatigue, burnout, and a deadened sense of situational awareness. Hazardous work conditions were accepted and managed. As a result, park leadership commissioned a planning group of 10 rangers with the goal of improving visitor safety on Grand Canyon’s many hiking trails and backcountry terrain. Their recommendation and call to action created the Preventive Search and Rescue (PSAR) team.

Evolution of PSAR: Best practices

Preventive search and rescue is a movement that promotes safety in arduous environments. For example, Yosemite National Park (California) focuses on educating visitors to use backcountry common sense, swift water safety, and public enjoyment of waterfalls from a distance. Yosemite implemented a permit system for climbing the popular Cable Route up Half Dome in summer 2010 in response to multiple fatalities from overcrowding. Delaware Water Gap National Recreation Area (Pennsylvania and New Jersey) uses PSAR to address water safety and proper use of personal flotation devices in an attempt to reduce the number of drownings. At Grand Canyon, PSAR was established in 1997 with the mission of reducing visitor injury, illness, and death during the hottest summer months.

The original PSAR crew consisted of four rangers who patrolled the Bright Angel and South Kaibab Trails. It is unclear how much time they dedicated to patrolling these trails, but according to original reports and corroborating interviews, PSAR rangers were either on the trail, interviewing hikers at trailheads, or staging at the Ranger Operations building. A strong volunteer force was also organized to augment the seasonal rangers for both trail patrols and rescue response.

In addition to the newly established staff of PSAR rangers, the park launched a media campaign with a “STOP, Heat Kills” message (fig. 2). Rangers posted signs along the corridor trails and distributed pamphlets, flyers, and general information to the visitor centers, backcountry office, and other informational areas throughout the park. Additionally, managers decided to close the South Kaibab trailhead to visitor parking, requiring the use of the Grand Canyon shuttle bus to access the popular trail. The lack of water availability in combination with this trail’s precipitous gradient and extreme sun exposure generated frequent rescues before creation of the PSAR program.

A stop sign with a detailed message about dangers of hiking in hot conditions.
Figure 2. Used in the late 1990s, the original PSAR sign delivered the message, “STOP, Heat Kills.”

NPS Photo

Bill Vandergraff, longtime backcountry ranger and SAR expert, said the closing of the South Kaibab trailhead to private vehicle traffic was instrumental in reducing the number of unprepared hikers from reaching this more problematic and challenging trail. “Prior to this closure,” Ranger Vandergraff stated, “people would drive in there, walk to the edge, look down, and get sucked right in. With the closure in place there is effort required to get out to the South Kaibab Trail; the road is closed and you need to take the shuttle bus. This has significantly reduced distress calls on the South Kaibab Trail.”

Nineteen years later, the PSAR team has evolved into a close-knit group of rangers who are dedicated to inner canyon public safety through the application of emergency response skills and science-based planning. Over the last two decades, advances in technology, improved hiking gear, and increased availability of backcountry information have shaped the playing field on which PSAR operates. Today, preventive search and rescue has adopted the team mentality and consists of seven seasonal rangers and one full-time supervisor. In addition to paid rangers, the program staffs 60 trained volunteers who supplement and amplify outreach efforts. Volunteers attend a two-day training at the end of April followed by two to three days of shadowing rangers on trails, for a total of 30–40 hours of preparation for the busy time of year.

The PSAR season runs from April through October, with the bulk of trail patrols occurring from May to mid-September. The team now regularly patrols the Bright Angel, South Kaibab, North Kaibab, and Hermit Trails. Every day during the season, several rangers and volunteers deploy onto corridor trails and slowly patrol down into the canyon. They take positions at natural bottlenecks on the trails close to common rest areas; their goal is to educate visitors descending farther into the canyon on topics such as personal preparedness and safe hiking practices. Many hikers have well-planned trips and many do not. Over the years, the original message of “STOP, Heat Kills” has evolved into “Hike Smart,” a more personalized and positive messaging campaign (fig. 3). Prevention is achieved through signage in conjunction with face-to-face encounters as rangers and volunteers patrol the corridor trails.

Composite graphic showing two signs: (1) A sign used from 2000 to 2010 that says "Down is optional, up is mandatory. Grand Canyon Search and Rescue." And (2) a sign with the message "Grand Canyon: Hike Smart."
Figure 3. Signs and media were updated between 2000 and 2010 with more realistic and tangible messaging. The “STOP, Heat Kills” sign was replaced by one that relays the more positive yet cautionary message to “Hike Smart.”

“Prevention through education” is PSAR’s primary mission, although responding to down-trail medicals and SARs is just as important. When the program was first established, PSAR rangers typically practiced at the first responder level. Today, all PSAR rangers are trained and certified to operate as EMTs or paramedics in the backcountry, developed area or “front country” ambulance settings, and helicopter medevac environments. Rangers are also trained in search and rescue, technical rescue, and many other emergency response skills (figs. 4 and 5). The combination of patrolling Grand Canyon’s trails one day and staffing the ambulance the next generates a rich blend of experience, judgment, and skill. PSAR rangers need to be self-sufficient, educated, and prepared to lead or guide those who are in harm’s way. Ranger Vandergraff commented on the progression of PSAR over the past decade: “The level of professionalism by setting standards based on certifications, a ranger’s training, and in-service group trainings has greatly improved our professional response—an important component of public safety.”

Helicopter medevac rangers wheel a litter up the Bright Angel trail for a major medical evacuation.
Figure 4. Helicopter medevac rangers wheel a litter up the Bright Angel Trail for a major medical evacuation.

NPS/C. J. Malcolm

PSAR rangers and helitack staff rescue a hiker on the Bright Angel Trail.
Figure 5. PSAR rangers and helitack staff rescue a hiker on the Bright Angel Trail. This individual tripped, breaking his leg, and was litter-carried to an awaiting helicopter.

NPS/C. J. Malcolm

Search and rescue: A discretionary function

What is a SAR? While there are many definitions, search and rescue is the search for and provision of aid to people who are in distress or imminent danger. A SAR may be as simple as assisting an individual with a sprained ankle to return safely to a trailhead, as perilous as rescuing an injured climber on Rocky Mountain National Park’s “Diamond” traditional climbing route, or as involved as multiday searches for individuals lost at sea or in wilderness settings. Saving lives is the ultimate goal of all search-and-rescue personnel.

The National Park Service further delineates SARs as major or minor, distinguished only by cost: major SARs accrue costs greater than $500 while minor SARs are less costly. Furthermore, expenses associated with major SARs are recoverable through annual reimbursement by Congress. Staff hours, equipment replacement, and helicopter medevacs are typical items that can rapidly inflate the expense of a rescue. The Park Service spends nearly $5 million annually rescuing visitors.

Is a park obligated to provide search and rescue? In a 1992 landmark decision, the 10th Circuit Court of Appeals ruled in Johnson v. US Department of the Interior that search and rescue is a “discretionary function” of government that is protected under general rules of exception of the Federal Tort Claims Act at 28 U.S.C. § 2680(a). Mr. Johnson, described as an inexperienced mountain climber, fell to his death on Buck Mountain in Grand Teton National Park. His family subsequently sued the Department of Interior claiming the park failed to properly warn him of the dangers of climbing and failed to initiate a rescue attempt within reasonable time. The 10th Circuit legally affirmed NPS testimony that “(1) the inherent dangers of mountain climbing are patently obvious; (2) both manpower and economic resources should be conserved … during emergency situations; (3) it would be impractical if not impossible to test competency, monitor equipment use, or ‘clear’ the mountain given limited available manpower and economic resources; and (4) many park visitors value backcountry climbing as one of the few experiences free from government regulation or interference.” The 10th Circuit Court of Appeals ruling further clarified a search-and-rescue team’s duty to respond, as follows:

No statute imposes a duty to rescue, nor are there regulations or formal Park Service policies which prescribe a specific course of conduct for search and rescue efforts. Instead, the decision if, when, or how is left to the discretion of the SAR team. Therefore, the rangers must act without reliance upon fixed or readily ascertainable standards when making a search and rescue decision in the field.

This judgment reaffirms that backcountry dangers are “patently obvious” and safety of an individual is a personal responsibility. Nevertheless, the National Park Service ardently strives to educate the public about wilderness dangers through solid preventive messaging.

Incorporating science

In 2011 a movement was initiated in preventive search and rescue to expand the team’s awareness and understanding of Grand Canyon hikers. We began to capture specific weather indicators and trail data to serve as benchmarking tools for year-to-year PSAR analyses and accountability. Rangers and volunteers now complete daily patrol logs documenting key data components: trail hours, patrol times, trails patrolled, general contacts, preventive actions, hiker assists, and major medicals (fig. 6).

The log used to record details of a preventive search and rescue patrol, including notes on parties encountered on trails and assistance rendered.
Figure 6. Daily patrol logs are filled out by PSAR staff following their patrols and provide information for evaluating and refining strategies designed to prevent trail mishaps.

During patrols, members of the PSAR team record the number of hikers they interact with on the trail. This is called a “general contact.” A “preventive action” is recorded each time a ranger determines the need to further educate a visitor, offering some form of corrective advice based on poor personal preparedness: hiking beyond one’s abilities, inadequate food and water, improper clothing or gear, or lack of area knowledge and plan. When a preventive action is recorded, a general contact is counted as well (see fig. 6). The ratio of general contacts to preventive actions highlights two indicators: PSAR outreach and the level of preparedness among those hiking in the canyon. A “hiker assist” documents each time a visitor requires physical, medical, or psychological intervention by PSAR rangers or volunteers. Last, a “major medical” involves paramedic-level interventions that often require a litter-carry or helicopter medevac (see figs. 4 and 5).

Statistics on Grand Canyon’s annual SARs and hiker assists are kept as separate figures; for example, an average of 300 SARs and an additional 530 hiker assists occur per year. Hiker assists characteristically are similar in scope to minor SARs, but are separated demographically to hikers in distress on corridor trails. However, when combined with Grand Canyon’s annual SARs, they demonstrate the overwhelming response of park personnel to backcountry travelers in need.

Throughout summer 2015 the PSAR team contacted 117,267 people hiking down Grand Canyon corridor trails (table 1).[1] Of these, 28,478 (24%) required some form of directive advice in the delivery of a preventive message and safe hiking education. Three hundred fifty of those general contacts required assistance hiking out of the canyon, a “hiker assist.” This type of assistance ranges from simple equipment repairs (e.g., shoes falling apart) to major heat illness interventions, such as rapid cooling, hydrating, and other advanced life support measures. PSAR rangers record hiker assists in more detail on a separate form. A number of demographics and variables are gathered, such as age, gender, location, need for assistance, and treatment or care rendered. Ranger hours spent patrolling trails are also trended and compared to annual park visitation, general contacts, and other indexes (table 2).[2]

[1]Table 1 reveals a decrease in hiker assists in 2014—a trend that continued into the early 2015 hiking season. One possible explanation for the decline is that the PSAR training in 2014 was greatly enhanced, improving the skills and confidence of the patrol rangers and trail volunteers.

[2]Table 2 reveals a decrease in patrol hours in 2014. In particular, afternoon patrols were reduced along the Bright Angel Trail following installation of the new Indian Garden weather station, which allowed adjustments to be based on temperature. Along the North Kaibab Trail, patrol reductions were related to staffing and hiring problems during the first half of the year.

Table 1. Contacts between PSAR staff and hikers along Grand Canyon corridor trails

Year General Contacts* Preventive Actions Hiker Assists Major Medical Assists
2015 117,267 28,478 350 11
2014 97,654 25,420 383 26
2013 92,044 29,831 617 24
2012 72,461 27,717 621 19
2011 80,083 33,992 685 16
Total 459,509 145,438 2,656 96
*Includes preventive actions.
Notes: Data reflect trail activity from 1 May to mid-September. PSAR rangers and volunteers carry hand counters and patrol logs to tally and report daily statistics.

Table 2. Patrol hours along Grand Canyon corridor trails as part of PSAR

Year Trail Total GRCA Park Recreation Visits
Bright Angel South Kaibab Hermit North Kaibab Other
2015 1,785 1,217 272 407 76 3,756 5,520,736
2014 1,663 1,135 236 289 295 3,618 4,756,771
2013 1,894 1,193 253 1,133 135 4,478 4,564,840
2012 1,540 973 292 739 121 3,587 4,421,352
2011 1,373 756 70 615 36 2,851 4,298,178
Total 8,225 5,274 1,123 3,183 663 18,290 23,561,877

In 2012, we began a comprehensive data analysis with the goal of identifying trends and validating long-standing assumptions. For example, we hypothesized that a physiological environmental temperature threshold exists in hikers who call for assistance; furthermore, at a specific temperature the PSAR team will experience a marked increase in down-trail distress calls. We then collected weather data from Indian Garden Ranger Station, a middle point in the canyon that most accurately reflects weather models along the South Kaibab and Bright Angel Trails. We compared maximum daytime highs to heat-related hiker assists along both of these trails. Subsequently, we discovered a strong relationship between heat-related hiker assists and maximum daytime temperatures.

From 2011 to 2013 a consistent pattern reveals a physiological temperature threshold spiking at 95°F (35°C) and hotter (fig. 7). Hiker assists at temperatures below this threshold occurred at a rate of 6.1 heat-related assists per 1,000 general contacts, whereas at temperatures at or above the threshold, heat-related hiker assists increased to an average of 10.4 per 1,000 general contacts, a 71% increase in distress calls. Historical weather data reveal that 1996 had the most days above 95°F of any year in the previous 25; that year holds the rec­ord for SARs (482), heat-related fatalities (5), and days above 95°F (65 days) (fig. 8).

Number of heat-related assists rendered on Bright Angel and South Kaibab Trails per thousand contacts from 2011 to 2013. The number hovers around 6 until the temperature reaches 95 degrees Fahrenheit. Above that temperature the number rises to 9 or more.
Figure 7. At 95°F (35°C) and hotter, a 71% increase in hiker assistance activity occurs. This is termed a heat threshold among Grand Canyon’s hiker population. (p < 0.001). The data are presented in the linked file.

Source: Indian Garden weather station

Number of days with maximum temperatures above 95 degrees Fahrenheit at Indian Garden between 1 May and 15 September from 1986 to 2012. The greatest number of days was 65 in 1996. The average is 45 out of a possible 70 days. See linked data table.
Figure 8. In 1996, Grand Canyon experienced the most days above the 95°F (35°C) heat threshold in a 25-year period and conducted a record-setting 482 search and rescues. The Preventive Search and Rescue program was established the following year. The data are presented in the linked file.

Source: Indian Garden weather station

This dramatic increase in hiker assists on days above the temperature threshold has the potential to tax ranger resources to the limit. Rescuer fatigue and resource depletion are serious concerns that compound the possibility of rescuer injury or illness. As Chief Phillips acknowledged, one call and “you’re spent for the rest of the day.” However, with advanced warning—days predicted at or above 95°F—both PSAR staff and the visiting public can profit from improved safety and hiker assist outcomes afforded by better information gathering and planning.

A big help to the enhancement of trail safety was the 2014 installation of a new weather station at Indian Garden (EW5243) and the 2015 Phantom Ranch weather station (EW9070) replacement of outdated equipment of the National Oceanic and Atmospheric Administration (NOAA) (fig. 9). These modern systems allow us to monitor real-time trail conditions with added meteorological values being measured to further refine physiological distress in relationship to environmental conditions: solar radiation (also called solar power density), which is far more important than temperature alone in order to describe the physiological burden for hikers); UV index; barometric pressure; wind speed and direction; dew point; and precipitation. Both of these weather stations are connected via a newly installed dish uplink system linked to ranger facilities on the canyon rim and ultimately to NOAA, MesoWest, and PSAR databases. This network is capable of hosting a multitude of future safety-related voice and data services in this remote and austere environment.

PSAR rangers install a Davis weather station at Indian Garden Ranger Station in 2014.
Figure 9. PSAR rangers install a Davis weather station at Indian Garden Ranger Station in 2014. The device records added meteorological values such as solar radiation and provides valuable microclimate data.

NPS/C. J. Malcolm

This innovative Canyon Emergency Information System (CEIS) was designed, built, and installed by Dr. Hannah Heinrich, longtime Grand Canyon volunteer and chief scientific PSAR advisor. CEIS is in its second year of interruption-free operation with future plans of linking weather data and other visitor safety–related messages to real-time displays at trailheads, inner canyon ranger stations, visitor centers, and backcountry permitting offices. CEIS can also provide a publicly accessible Internet presence on the corridor trails. This is a tremendous step toward providing real-time information for the five million annual park visitors.

As data analysis continues, the PSAR team will shape its upcoming staffing based on updated study results: trail patrols and hiker education will be reinforced on days above the temperature threshold. During summer 2015 (Norwil et al. 2015), the PSAR team conducted the OMB approved Hiker Hydration Study evaluating the drinking habits of hikers entering Grand Canyon. More than 1,000 hikers filled out questionnaires over three weekends with an outstanding 75% response rate. These data are now under analysis and in draft form.

The goal remains the same: we will continue to learn and anticipate Grand Canyon hiker habits and trends to reduce visitor injury and death, and we will use our workforce as efficiently as possible to promote rescuer safety and optimal response to calls for assistance.

Remaining accountable to the public

Everyday PSAR operates a step behind the public. Some visitors make dangerous plans and casually descend into the canyon with unrealistic goals in mind. Out of the more than 117,000 people our staff encountered during summer 2015, more than 28,000 required persuasion to adopt different plans. Attempting to influence individuals to change their behavior while they are happily hiking into Arizona’s great chasm takes more than talent. Strong salesmanship, customer service skills, and knowledge of human behavior are cornerstone arts that PSAR rangers must master. Improved training, knowledge of the customer—the hiking public—and centering preventive strategies on scientific data remain PSAR’s guiding objectives. The more we learn about the motivational values of those who descend into the canyon, the more proactive PSAR can become in developing techniques for educating hikers on improved personal preparedness. Science in concert with a learning organization approach makes this task easier.


All information in this article is derived from SAR and dispatch logs at Grand Canyon National Park, interviews with the aforementioned rangers, and findings from original studies designed by the PSAR team. Additionally the Preventive Search and Rescue Impact Report (cited below) contains much of the material for this article. PSAR rangers Emily Pearce and Joelle Baird contributed to this article. Special thanks go to Ken Phillips and Bill Vandergraff.


Johnson v. United States Department of Interior, 949 F. 2d 332, 60 USLW 2356 (10th Cir. 1992). Federal Reporter, Second Series. Available at

Malcolm, C. J., and H. Heinrich. 2012. Preventive search and rescue impact report. National Park Service, Grand Canyon National Park, Arizona, USA.

Norwil, E., C. J. Malcolm, and H. Heinrich. 2015. Hiker hydration study. Abstract and summary. National Park Service, Grand Canyon National Park, Arizona, USA.

About the author

C. J. Malcolm, with a master’s in Organizational Leadership, is a former ranger paramedic and PSAR supervisor at Grand Canyon National Park, 2010–2016. He currently works at Gunnison Valley Hospital as a paramedic captain and emergency management coordinator. Hannah Heinrich, PhD, MSCS, is a former volunteer and chief scientific advisor for the PSAR team. Dr. Heinrich currently resides in Germany and is a recognized expert regarding occupational health and safety with the German government and the European Union. She assisted with all data analysis and graph creation. Malcolm can be reached by e-mail.

Grand Canyon National Park

Last updated: March 21, 2021