Map and compass

Your phone's GPS is excellent as long as it has battery. A paper map and a baseplate compass (transparent, with a rotating bezel) don't fail. Also download offline maps on your phone before heading into any natural area.

Parts of a baseplate compass

• Direction-of-travel arrow: engraved on the baseplate; it points where you will walk.
• Rotating bezel: the ring marked with degrees (0–360°).
• Orienting arrow and lines: inside the bezel; they turn with it.
• Magnetic needle: its red end points to magnetic north.

Magnetic declination

The needle points to magnetic north, not the true north of maps. The difference (declination) changes with location and over the years. In some parts of the U.S. it is small, only a few degrees, so on short hikes the error is minor; in other regions it can exceed 10°. Check the current value in NOAA's declination calculator (ngdc.noaa.gov/geomag) or in the margin of your topographic map, and adjust it on the compass if it has a declination screw.

Taking a bearing from the map and following it

1. Place the compass on the map with one edge of the baseplate connecting your position and your destination, and the direction-of-travel arrow pointing toward the destination.
2. Turn the bezel until the orienting lines are parallel to the map's north-south lines, with the orienting arrow pointing to the map's north. (It doesn't matter where the needle points at this step.)
3. Read the bearing at the index mark; correct for declination if your compass doesn't do it.
4. Lift the compass, hold it level in front of your chest, and turn your whole body until the red part of the needle sits inside the orienting arrow ("red in the shed").
5. Walk in the direction of the travel arrow. Pick a distant object on that line (tree, rock), walk to it, and repeat. Don't walk while staring at the compass.

Orienting the map

Place the compass on the map with the travel arrow toward the map's north and turn the map and compass together until the needle points to that north. Now what you see on the map matches what is in front of you: identify hills, rivers, roads, and towers.