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Field guides / Casting tracks

How to photograph, measure and cast a track

A good track is evidence for about as long as it takes the next rain to arrive. Photos come first, measurements second, the cast last. Here's how to do all three so the result is worth keeping.

6 min readPrintable checklistsUpdated October 2026

The order matters

Casting is the fun part, but it destroys the track. A cast of a single print without photos and measurements is a nice paperweight. Do it in this order and you'll have the full record even if the cast cracks.

  1. Protect the trackway so nobody walks on it, you included.
  2. Photograph every print, from overall to close-up.
  3. Measure the prints and the distances between them.
  4. Cast the best one or two.
  5. Label and log everything before you leave.

First, slow down

Before you get excited, walk around the outside of the area and look at the bigger picture. Where does the trackway start and end? Are there human tracks alongside, or a bear's? Did snowmelt or rain change the shape? Note the weather in the last day or two; it tells you how old the tracks could be.

Photographing a track

Take far more photos than you think you need. They're free, and you can't go back.

  1. The context shot. Stand back and show where the track is: the creek, the road, the whole line of prints. Include something recognisable.
  2. The mid shot. A few prints in a row with a tape measure laid alongside the trackway.
  3. The straight-down shot. Camera directly above the print and level with the ground (not at an angle, which distorts length), with a scale right next to the print at the same depth. Fill most of the frame with the print. Do this for every print you can.
  4. Raking light. Shade the print with your body or a jacket and hold a torch low to one side, almost along the ground. Shoot again with the light from two or three different directions. Toe marks, ridges and creases appear that you can't see in flat daylight.
  5. Your boot for comparison. Press your own boot print into the same ground nearby and photograph it with the same scale. It shows how deep a known weight sinks in that soil.
Photographing a track: camera straight above, scale beside the print, torch held low to the side for raking light scale straight down, level torch low, from the side Shade the print first. Raking light throws shadows intoevery toe mark and ridge.
A scale at the same depth as the print, a camera held square above it, and low light from the side: the three things that make a track photo useful to someone else.

Phones are fine. Turn off any "beauty" or AI enhancement, keep location tagging on for your own copies, and use the 1x lens rather than a wide-angle, which bends straight lines near the edges.

Measuring a print and a trackway

Footprint with length, ball width and heel width measurements marked Length Width at the ball Width at the heel Midfoot: note any crease or ridge Measure length from the back of the heel to the tip of the longest toe.
Write every number down with its unit. Measure in a straight line, and measure two or three prints from the same trackway: real feet vary a little from print to print; carved fake feet often don't.

Also note:

  • Toes: how many, how they're spread, and whether any are bent or missing.
  • Claw marks just ahead of the toes. Bears and dogs leave them; people and the tracks reported as Bigfoot don't.
  • Depth at the heel and the toe, compared with your own boot print in the same ground.
  • Skin ridges ("dermal ridges"): fine lines like fingerprints, sometimes visible in very fine mud.
  • Which foot it is, left or right, and which way it's heading.

Then measure the trackway: step (heel of one foot to the heel of the next), stride (heel to heel of the same foot) and straddle (the width of the whole trackway). There's a diagram in the expedition guide. Count how many prints there are, and note where the trail goes onto hard ground and disappears.

Bear or Bigfoot?

A black bear's hind foot looks surprisingly human, and when a bear's hind foot lands on or just ahead of its front print, the two merge into one long flat-footed print. Look for claw marks just ahead of the toes, a toe arrangement where the biggest toe is on the outside (a bear's smallest toe is on the inside, the opposite of ours), and a second set of prints with the same spacing.

Dental stone or plaster?

Dental stone (use this)

  • Much harder: survives being lifted from mud and scrubbed clean
  • Picks up finer detail
  • Can set in wet ground and even standing water
  • Less fussy about the exact water amount
  • Sold by forensic and evidence suppliers, often pre-measured in bags

Plaster of Paris

  • Cheap and sold everywhere
  • Soft and chalky; big casts snap unless reinforced with sticks
  • Struggles in wet ground
  • Fine for practising on dog and deer tracks
  • Avoid "patching" or hobby plasters, which set soft

How much to bring: a big print 15 inches long and a couple of inches deep can easily take 3 to 5 pounds of dental stone to make a cast thick enough to survive. Pre-measure it into heavy zip bags at home and mark each bag with the water line or amount.

Casting, step by step

  1. Clean the print gently. Lift out loose leaves, twigs and pebbles that fell in after the print was made. Leave anything pressed into it. No blowing; that blasts away fine detail.
  2. Build a dam. Bend a strip of cardboard, plastic or flashing into a ring an inch or two bigger than the print, clip it with a paper clip and press it lightly into the ground. No strip? Mound up soil around the print. On a slope, the dam is essential.
  3. Mix. Add powder to water, not water to powder. For dental stone, follow the bag; as a rough guide, around 9 to 12 fluid ounces of water per 2 pounds of powder. The easy field method is to pour the water straight into the bag of powder, seal it and knead it for a couple of minutes until it's smooth and lump-free, like thick pancake batter or melted ice cream.
  4. Pour gently, beside the print. Pour onto the ground just next to the print, or over a spoon or spatula held low, and let the mix flow in. Never pour from height straight into the deepest part; it blasts away the detail.
  5. Fill it up. Keep pouring until the print is covered and the cast is at least an inch thick, thicker for big prints. With plaster, lay a couple of clean sticks across the middle and cover them as reinforcement.
  6. Label it while it's soft. Scratch the date, time, place and your initials into the back with a twig once it firms up a little.
  7. Wait. Dental stone usually firms in about 20 to 30 minutes; give it longer in cold or wet ground, and at least an hour in standing water. Plaster needs at least 30 minutes. Tap it with a knuckle: a hard "tock" means it's ready.
  8. Lift it from underneath. Dig around and under the edges and lift from below. Never pry it up with a stick from one side. Leave the dirt on.
  9. Wrap and carry flat. Wrap in newspaper or a towel (not plastic, which traps moisture) and carry it flat.
  10. Cure and clean later. Let it dry for a couple of days, then rinse off the soil under running water with a soft brush, working from the edges in. Dental stone can take a good scrub; plaster can't.

Tricky ground: snow, water and dust

Snow

Setting stone gives off heat and melts the print. Spray the print first with a forensic snow wax spray to make a thin shell, or chill the mix with snow and use a slightly thicker mix. Photograph extra carefully: snow tracks change shape within hours in sun.

Standing water

Dental stone can set under water. Some trackers sift dry powder gently into the water-filled print until it fills, then pour a normal mix on top. Give it at least an hour.

Loose dust and sand

Use a slightly runnier mix so its weight doesn't crush the detail, pour very gently, and let it set longer. Some people first mist the print with aerosol hairspray from a distance to firm the surface.

Thick mud

Great detail, but the cast grips. Dig out around it before lifting, and let it set fully first.

Casting kit

Track casting kit

Documenting

Casting

What to do with it

  • Keep the cast, the photos and your notes together, with the same reference number on each.
  • Don't paint the whole cast. If you want detail to show up, a light wash only in the low spots does it.
  • Take photos of the cast later under raking light too, from straight above, with a scale.
  • Send us a report with the photos and measurements. The reporting guide covers the details people will ask about.

More field guides

Bigfoot expeditionPlan a Bigfoot expeditionThe full playbook: picking a spot, gear, cameras, audio, night sits, tracks, hair, safety and ethics.18 min read · printable checklistTrail camerasTrail camerasChoosing a camera, height and angle, settings, theft-proofing, bait ethics and the rules on public land.7 min read · printable checklistReportingHow to report an encounterWhat makes a report hold up, keeping original files, privacy, and where to send it.4 min read · printable checklist

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