Grid-Down Guide

Skills

Map & Compass

Find your way when GPS and phones fail — reading a topo map, using a compass, declination, and simple tricks without either.

Photo: U.S. Department of Defense, Public domain

Why paper still matters

Phones die, GPS needs batteries, and cell maps don't load without a signal. A paper map and a baseplate compass weigh a few ounces and never run out.

  • Keep a road map of your region in every car.
  • Keep a topographic map of anywhere you hike, hunt or might evacuate through. The USGS offers free topo maps you can download and print: USGS topographic maps.
  • Download offline maps on your phone before you go (Google Maps, Gaia GPS, onX, CalTopo and others all support this).

Reading a topo map

  • Contour lines connect points of the same elevation. Lines close together = steep; far apart = flat.
  • V shapes in contour lines point uphill in a valley or drainage (the "V" points upstream).
  • Colors: green = vegetation, blue = water, brown = contours, black = roads, buildings and trails.
  • Scale: on a common 1:24,000 USGS map, 1 inch = 2,000 feet.

Using a baseplate compass

Take a bearing to a landmark

  1. Point the direction-of-travel arrow at the landmark.
  2. Turn the bezel (housing) until the red orienting arrow lines up under the red end of the magnetic needle ("red in the shed").
  3. Read the bearing at the index line. That's your direction in degrees.

Follow a bearing from the map

  1. Lay the compass edge on the map from where you are to where you want to go.
  2. Turn the bezel until the orienting lines run parallel to the map's north-south grid lines, with the orienting arrow pointing to map north.
  3. Adjust for declination (below).
  4. Hold the compass flat, turn your body until "red is in the shed," and walk toward the direction-of-travel arrow. Pick a landmark on that line, walk to it, and repeat.

Declination: true north vs. magnetic north

A compass points to magnetic north, which in the Inland Northwest is roughly 13–14° east of true (map) north, and it slowly changes each year. Many compasses let you set declination once. Otherwise, when going from map to field, subtract east declination; from field to map, add it. Check the current value for your location at NOAA's declination calculator.

No compass?

  • Sun: rises roughly in the east, sets roughly in the west. At midday in the Northern Hemisphere, it's due south.
  • Shadow stick: put a stick upright in the ground, mark the tip of its shadow, wait 15–30 minutes, mark it again. A line from the first mark to the second points roughly east.
  • North Star (Polaris): find the Big Dipper; the two stars at the end of its "cup" point to Polaris, which is almost exactly north.
  • Moss on trees is not reliable. Don't count on it.

If you're lost

S.T.O.P. — Stop, Think, Observe, Plan. Don't keep walking. Staying put makes you much easier to find. Make yourself visible, use three whistle blasts, and stay warm and dry.

Free offline reference: ATP 3-50.21 Survival covers land navigation in detail.

Sources: USGS — Topographic maps · NOAA — Magnetic declination · ATP 3-50.21 Survival

Watch & learn

Videos stream from YouTube, so they need an internet connection. Everything else on this page works offline.