Sasquatch Field

Research Manual

Never stop because you are afraid - you are never so likely to be wrong.

                                                                                                  --Fridtjof Nansen 



C. Leigh Culver


Copyright © 2010-2013 C. Leigh Culver.  All rights reserved.





Historic data and current indications suggest that sasquatches are largely nocturnal. Because of this, night operations are a very necessary part of sasquatch research. This article will discuss methods and techniques for operating at night. It should be noted that night operations don’t necessarily rely on night-vision devices. Many of the techniques discussed will also apply to other conditions of low visibility such as fog, rain and snow.




Night travel can be dangerous and strenuous. Navigation is also more difficult at night. Before conducting a night operation the operational area should have been pre-scouted. All team members should be knowledgeable of such factors, as terrain, avenues of approach, and any key danger zones (steep cliffs, fast-moving rivers, areas with decreased radio reception, etc.). Additionally, all persons should be knowledgeable of any operational and/or contingency plans, their area of responsibility and communication procedures.


When operating at night you need to be aware and "switched-on" to your surroundings. You should be able to differentiate between what is normal, and what is not. With time and training you will be able to subconsciously catalog the various sights and sounds and develop a mental alarm when something is not right. Being aware is something that can be developed through training.




A lot of people will not admit this, but many people do have a fear of the dark. Factor in the reality that you are looking for a creature known as sasquatch and the potential fear factor increases exponentially. This author knows of no sasquatch encounter that has ever turned violent other than a couple of historic references where the sasquatches were attacked first.


During any night operation the minimal number for a team should be two persons for the sake of safety. We have conducted operations where single individuals were spread out within the operational area; however, our regular protocol is to use the “buddy system.”  Having said that, I will say that there may be times when it is practical for a single individual to go out alone. This individual, however, should be very wilderness self reliant and appropriately equipped.




Night-vision enhancing devices will be discussed in an article on Specialized Equipment so this section will focus on physical sight. The eyes contain two types of photoreceptors: rods and cones. The cones are primarily active in bright light, are capable of color vision, and are responsible for high spatial acuity. At night, the eye uses the rods. Rods cannot differentiate color, are easily blinded by light, and have a lower spatial acuity. This creates a central blind spot, which causes the viewer to miss larger objects as distances increase. The diagram below will demonstrate the anatomy of the eye and the locations of the rods and cones. You will see that the cones are located in the central, posterior area of the eye and you can imagine how this area of the eye can’t see at night.



Persons who perform daytime tasks prior to performing night operations will experience some reduction to their night-vision. Intense exposure to sunlight, even several hours, prior to night operations, can delay ones adaptability to the dark by several hours. One way to help avoid this is by wearing sun glasses or, if you can find them, neutral-density sunglasses when in bright light. Neutral-density sunglasses are used by pilots and by the military.




When operating in the dark you should use the “night-vision-scanning” technique. This technique helps overcome physiological limitations and reduces illusions of vision. Night-vision-scanning will also protect your night-vision and dark adaptation capabilities. The technique involves slowly and regularly scanning from left to right, or right to left. When doing this the key is to avoid looking directly at the faintly visible objects. The diagram below demonstrates the technique.





During daylight hours we look at an object using central vision; that is, we look straight at the object. Due to the rods inability to operate well in the dark, and the resulting central blind spot, we must compensate. How we compensate is to use off-center, or peripheral vision. We do this by looking ten degrees above, below, or to the side of the object rather than look directly at the object. The diagram below demonstrates the technique.





It takes about 30 to 40 minutes for your eyes to adapt to the dark. After about 30 minutes your visual sensitivity maxes out (to about 10,000 times that of normal). Sensitivity will still increase after this period, however, at a much slower rate.


Darkness reduces visual acuity to about one-seventh that of daylight levels. This means that only large objects will be seen. Color perception also decreases when light decreases. Night-time field researchers will only be able to distinguish light and dark colors to the degree of reflected light intensity.


Once adaptation to the dark occurs, any exposure to bright light (matches, headlamps, flashlights, vehicle headlights, etc.) can affect your night-vision. Full recovery from such exposure may require up to 45 minutes until your night-vision returns. Should such unexpected exposure occur, you should attempt to preserve your night-vision by covering or closing one eye. When the light source is no longer present, the eye that was covered will continue to provide night-vision capability. If you must use light in order to operate in the dark, use headlamps with red lenses. This will help maintain your night-vision as well as have a minimal impact on the operational environment.




Objects that are viewed for more that two to three seconds tend to fade-out into one solid color. This will still occur when off-center-viewing is used. To overcome this phenomenon you should avoid looking at any object for more than two or three seconds. By shifting your eyes from one off-center point to another you will be able to continue seeing the object in your peripheral vision.




If you stare at any single point of light or a prominent object for too long, it will seem to move. This is the most common reason why field researchers imagine that they see trees moving at night. “Placing” an object against what is being viewed, such as your finger at arm’s length, can help prevent this.




At night, light sources can often be seen by quite a long distance. A brief list of lighted sources will demonstrate how far away some known light sources can be seen. This information is based upon U. S. Army studies.


  • Vehicle Headlight - 0 to 5 miles

  • Bonfire - 0 to 5 miles

  • Flashlight - 0 to 1.5 miles

  • Lighted Match - 0 to 1 mile

  • Lighted Cigarette - 0 to 1000 yards


Due to the nature of how our eyes operate at night, white light can be seen three times farther than red light of the same intensity. It is hypothesized that sasquatches have an increased ability to see at night; with this in mind, red filtered light (example - Red LED Headlamp) should be used whenever light is needed during night operations.




Acoustical enhancing devices will be discussed in the article on Specialized Equipment so this section will focus on physical methods. At night our hearing becomes much more acute. With decreased visual ability, we tend to concentrate more using our other senses; especially, our auditory sense. Changes in temperature and humidity can play a role in our ability to hear at night. Sounds are transmitted farther in wet weather and at night than in dry weather and in the daytime. Terrain features can greatly affect sound as well.


There are sounds that are usual to the natural environment, as well as, sounds that are not. When performing night operations we need to keep sound to a minimum. The list below will give you an idea of how far various sounds can be heard at night. This data is based upon U. S. Army studies.


  • Normal Footsteps (0 to 30 yards)

  • Footsteps over leaves and branches (0 to 80 yards)

  • Movement of a large group of persons on foot

On a dirt road - 0 to 300 yards

On a highway - 0 to 600 yards

  • Motor vehicle movement

On a dirt road - 0 to 500 yards

On a highway - 0 to 0.6 miles

  • Metal on metal - 0 to 300 yards

  • Conversation - 0 to 300 yards

  • Axe blow - 0 to 500 yards

  • Screams (human) - 0 to 1,500 yards


There may be times when it is difficult to hear anything at all. By cupping your hands behind your ears sounds may become more amplified. Hearing can also amplified by opening your mouth when listening.


Inclement weather, such as wind or rain, or when wearing head gear, can greatly affect your ability to hear. In such situations there is a trick that you can do. Being that the ground is denser than air, we know that sounds travel farther through the ground. One trick that can sometimes be performed is to simply put your ear to the ground and listen. Alternatively, you can place your ear to a stick (about six inches long) that has been driven several inches into the ground and then listen. It is difficult to determine direction with these methods; however, they may work when listening for a creature as heavy as a sasquatch who might be walking in your immediate area.




Smell is often our least used sense, though we tend to use it more when operating at night. We only use about two percent of our olfactory potential; however, the more time we spend in the bush, the keener our sense of smell becomes.


Based upon numerous reports, we know that sasquatches are often described as having a very characteristic pungent odor--hence the term “skunk ape” that is used in the southeastern part of the United States for describing sasquatches. This odor has sometimes been described as being:


  • Skunk-like

  • Dead animal-like

  • Wet animal-like

  • Feces-like

  • An eye-burning combination of the above




When the sun sets, the air cools causing odors to float downhill. When the sun and temperatures rise, odors rise. As odors rise, the more likely they are to be picked up and carried by the wind. By facing into the wind at a 45-degree angle, relaxing, and sniffing sharply, we can better pick-up odors. With increased bush-time and practice we can improve our sense of smell.


Another way we can use the sense of smell is via the scent ability of other animals. Surrounding animals may alert us by their behavior to the fact that a sasquatch may be in the area. Keep in mind that this works both ways and that a sasquatch may become aware of us in a similar manner.




Fatigue can be a factor during night operations due to the fact that most persons are awake during the day and sleep at night. Sleep is a vital physiological function. Optimal sleep, both in quantity and in quality, is necessary for maximal performance and alertness. Reduced or degraded sleep can significantly decrease or impair performance and alertness. The average adult human requires 8 to 8.25 hours of sleep. The overall range of individual sleep requirements is around 6 to 10 hours.




Circadian rhythm plays a vital role in human sleep. Circadian rhythms are cycles within a living organism that take about 24 hours in order to complete from start to finish. The circadian clock regulates the sleep/wake cycle, body temperature, hormone release and cognitive performance. Due to the circadian clock the maximum time of human sleepiness occurs between 3 to 5 AM. A second period of sleepiness occurs in the mid afternoon, regardless of whether lunch was eaten or not.




It is best to get some sleep during the day prior to a night operation to insure maximum performance. You should take the perspective that some sleep is better than no sleep. If getting sleep during the day is not possible, it is recommended that a nap strategy by used. Persons who are performing the night operation should attempt to take a nap just prior to going out. To avoid sleep inertia, the nap should be limited to no more than 45 minutes or extend the nap to about 2 hours.




Caffeine can be used strategically during night operations. Caffeine is an effective stimulant but one to which many people have become less sensitive due to regular and heavy use. To enhance caffeine’s stimulant effects, you should cut back significantly on caffeine (but not stop its use) for at least two days before a planned night operation (preferably a week) and avoid caffeine until just prior to starting the night operation. Caffeine takes about 30 minutes to have an effect with peak plasma levels occurring around 30-60 minutes. Harris Lieberman lists the following amounts of caffeine per beverage in the HANDBOOK OF HUMAN PERFORMANCE:




BEVERAGE                           CAFFEINE AMOUNT (mg) 


Coffee 5 oz cup

Drip Method                                         90-150 

Percolated                                           64-124

Instant                                                 40-108

Decaffeinated                                         2-5


Tea, loose or bags 5 oz cup

5-Minute Brew                                      20-50


Tea products

Instant 5 oz cup                                    12-28

Iced Tea 12 oz can                               22-36


Chocolate products

Hot Cocoa 6 oz                                       2-8

Milk Chocolate 1 oz                                1-15

Sweet Dark Chocolate 1 oz                     5-35

Chocolate Milk 8 oz                                  2-7

Chocolate-Flavored Syrup 2 tbsp                4


Cola beverages 12 oz

Most colas                                           36-46




Decreased sleep and fatigue can decrease brain levels of norepinephrine resulting in performance degradation. L-tyrosine is an amino acid required for the manufacture of the neurotransmitters: norepinephrine, epinephrine, and dopamine. Studies with U. S. Navy SEALS and U. S. Army Special Forces have demonstrated that supplementation with L-tyrosine can increase blood and brain levels of tyrosine which promotes increased production of brain norepinephrine. Increased levels of norepinephrine can improve attentional focus, mental alertness and can protect against cognitive performance decrement.


The above studies suggest a dosage of L-tyrosine of 150 mg/kg (one kilogram = 2.2 pounds) body weight, one to two hours prior to the night operation. Though there are no reports of any serious tyrosine side effects, tyrosine should not be taken if you are taking anti-depressants or medicines for Parkinson's disease, if you have diabetes, or if you are pregnant. Keep in mind that the above dosage of L-tyrosine is not intended for long term use and there is always a possibility of allergic reactions to any supplement. Such reactions may include breathing problems, tightness in the chest or throat areas, skin hives, itchy or swollen skin, or rashes. L-tyrosine may be purchased at most health or nutritional oriented stores.  As always, it it is recommended that you speak with your health care provider before considering taking L-tyrosine as suggested above.




The primary goal of night walking is stealth and the U. S. Army suggests a specific night walking style. Night walking requires a very different form of movement and technique. Typically when walking during the day we tend to use our calf muscles more. Night walking utilizes the muscles in the thighs and buttocks. This specialized walk takes some practice, but once mastered you will be able to move quickly and silently through the forest at night. This type of walking technique is taught throughout various military schools on night patrolling and is quite effective for our work.


The technique requires the walker to take short careful steps, lifting the left foot about knee high while balancing on the right foot. While still balancing the left foot is lowered gently and placed about six inches in front of the right foot. As the left foot is lowered the walker attempts to feel for any holes, twigs or rocks. If there are any twigs or rocks, they are gently swept away then the left foot is placed on the ground once the footing is determined to be solid. This step is then repeated with the right foot and so on. When moving at night it is a good idea to frequently stop and listen.


I personally prefer a walking method called the "Fox Walk" as presented by Tom Brown, Jr. When performed it looks a bit funny, but is a very effective method for moving quietly through the wilderness.  Here's how to do it.

  1. Touch the outside edge of your foot to the ground

  2. Roll your foot inward until it is flat on the ground

  3. Before adding your weight, is there a sharp stone, a rounded branch or any other object that would make a noise or irritate your foot?

  4. If so, reposition your foot

  5. Transfer your weight to your foot

  6. Repeat with your other foot



There are several forms of communication or signaling that are relevant to night operations. Each of these forms of signaling is oriented to maintaining stealth. Nighttime signaling may rely on sound, touch and sight.




Radio communication will be covered in a separate article. The main point to be aware of for night operations is that sound travels farther at night, therefore, radio communication must be performed in a quiet manner. Head phones or ear buds should be used. If using FRS/GMRS radios make sure the “roger-beep” feature is disabled and the “call” button should be avoided.




When performing oral communication at night you should whisper. There is a simple and effective method for whispering. You should take in a normal breath, exhale half of it, and then using the remainder of your breath, whisper your message into the other person’s ear.




There are many visual signal options. A team can use red LED lights for silent signaling in an area where you have line of sight. Another option, if using night vision devices, is to use infrared LED lights for signaling. Our team will sometimes use luminous clip-on LED marker lights or LED glow tubes on the back of our packs for when we are hastily leaving an area so that we can better keep track of everyone.


Other signaling options can include flashlights, luminous tapes, biodegradable tapes and chemical lights. Biodegradable tapes can be used to mark important areas from a previous scouting mission. You are only limited by your imagination as to what items to use or how to uses these items. Do keep in mind that anything a human can see, a sasquatch can see.




Audible signals are least used due to the fact that they can make your location known to not just your fellow researchers. Clickers or “crickets” as sometimes used by military forces are an option, however, they are not recommended.


It is interesting to note that sasquatches use similar tactics at night. One example is “wood knocking” that is often heard during sasquatch encounters. This author has had several close encounters where several sasquatches had surrounded the team and the sasquatches were using light wood tapping-like sounds to locate one another in relationship to us. Sasquatches will often use whistles in a similar manner for the same reason




If you or any of your team is in close proximity, as in a hide site, simply tapping, or squeezing your partner’s arm or shoulder can be used.




Nature provides a wide variation of environmental base-line and any moving thing, man or beast, disturbs that base line which results in track or sign. Tracking can be accomplished at night; in fact, tracking is actually easier at night. Tracking as a subject will be discussed in a separate article.




1.   Bonnet, M. H. 1994. “Sleep Deprivation” in Kryger, Meir H., Roth, Thomas, and Dement, William C., PRINCIPLES AND PRACTICES OF SLEEP MEDICINE, 2ND EDITION, (pp. 50-67), Philadelphia: W. B. Saunders Company.


2.   Brown, Jr., Tom. 1983. TOM BROWN'S FIELD GUIDE NATURE OBSERVATION AND TRACKING (pp.92-94), New York: Berkley Books.


3.   Culver, C. Leigh. 2008. "Sleep/Wake Cycle Management for the Tracking Team," Presentation, Tracking 2008 International Society of Professional Trackers Symposium.


4.   Deuster, Patricia A. and Singh, Anita, 1998. “Nutritional Ergogenic  Agents: A Compendium for the Special Operations Command,” (p. 32, Bethesda: Department of Military and Emergency Medicine Human Performance Laboratory, Uniformed Services University of the Health Sciences.


5.   Dinges, David F., Neri, David F., Rosekind, Mark R., 1997. “Sustained Carrier Operations: Sleep Loss, Performance, and Fatigue Countermeasures,” (pp. 12-13), Moffett Field: NASA Ames Research Center.


6.   Field Manual Headquarters, 2009. FM 3-55.93 LONG-RANGE SURVEILLANCE UNIT OPERATIONS, (pp. J1-J8), Washington DC: Department of the Army.


7.   Field Manual Headquarters, 2000. FM 3-04.301 AEROMEDICAL TRAINING FOR FLIGHT PERSONNEL, (pp. 8/10-8/11), Washington DC: Department of the Army.


8.   Lieberman, Harris. R., 1992, “Caffeine” in A. P. Smith & D. M. Jones (Eds.), HANDBOOK OF HUMAN PERFORMANCE, VOL. 2: HEALTH AND PERFORMANCE, (p. 52), London: Academic Press.


9.   Marine Corps Warfighting Publications, 2000. MCWP 3-11.3  SCOUTING AND PATROLLING, (pp. 5/1-5/3) Washington, DC: Department of the Navy.



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