Bearings To Two Peaks
Okay. Last lesson your compass was adjusted so it does the math for you. Declination's built in. You just read the number off the Needle and it's already correct.
Now we're going to use that to actually figure out where you're standing, using nothing but two peaks and some napkin math. This is triangulation, and it's Low Key one of my favorite things to teach because it feels like a magic trick the first time it works.
The problem this solves
Sometimes you know where you're going, but you don't know where you are right now. Maybe you wandered off trail a little following a deer path, or the trail forked twice and you lost track. You've got a map, a compass, and two mountains you can identify. That's enough.
What you need
You need to see two landmarks you can positively identify on your map. Peaks work great because they're pointy and obvious. A radio tower, a water tank, a distinctive saddle, any of that works too, as long as you're sure which dot on the map matches which thing on the ground. Guessing wrong here ruins the whole exercise, so take your time on the ID.
The steps
1. Orient your map to the terrain first. Before any numbers happen, turn the physical map in your hands until it matches the ground around you. The ridgeline on the paper should point the same way as the ridgeline in front of you. This is the thing my dad, Craig, taught me way before he ever let me touch a bearing. I thought it was backwards at the time. Why would you fumble with turning the whole map around when you could just trust the numbers? But orienting the map to the ground first is what actually made maps click for me. You're teaching your eye to see the land as a picture before you teach it to calculate anything. Full credit to Craig on that one.
2. Take a bearing to Peak One. Plant your feet, point the direction-of-travel arrow at the peak, rotate the housing until the Needle lines up in its box, read the number. Say it out loud. You know the drill by now.
3. Transfer that bearing onto the map. Find Peak One on your map. Lay your compass baseplate on the map with one edge touching that peak, then rotate the whole compass (map and all, or just the baseplate, whichever your model allows) until the orienting lines inside the housing point to true north on the map, matching your dial reading. Draw a light pencil line from the peak, back toward you, along that edge. That line is somewhere you are standing on it.
4. Do the same thing for Peak Two. Different bearing, different peak, same process. Draw that line too.
5. Where the two lines cross is you. That intersection is your position. Not roughly. Actually.
If you've got a third landmark handy, shoot a bearing to that too and draw a third line. In a perfect world all three lines cross at exactly one point. In the real world you'll usually get a small triangle instead of a single dot, because your bearings are never perfectly precise and neither is your pencil hand. That little triangle is fine. You're standing somewhere inside it. I did this once off two peaks and a radio tower and got a fix so tight it landed inside the actual clearing I was standing in. I sat down on a rock afterward and felt pretty smug about it for about ten minutes. Nobody was around to see it, which honestly is the correct way to feel smug about something like this.
Where people trip up
Mixing up which peak is which on the map. Sight both landmarks and write down notes before you touch a pencil, something like "Peak on the left, closer, more triangular, that's the one labeled 9,800 on the map." Don't trust your memory to hold two bearings and two peak identities at once while you're also drawing lines. Write it down.
Also, don't do this near your truck, your framed pack, or anything metal. The Needle doesn't care about your triangulation homework, it cares about magnetism, and it'll lie to you cheerfully if there's steel nearby.
Try it small first
You don't need real peaks to practice the mechanics. Pick two objects across a park or a big flat lot, take bearings, transfer them onto a rough sketch, see the lines cross. My opinion hasn't changed since day one of this course: practice this in a boring, flat, low-stakes spot before you need it for real up a canyon. If you can only do triangulation when the scenery is dramatic and you're calm, you can't actually do it yet.
Before next time
Try this at home with a hand-drawn sketch of your street. Pick two landmarks you can see from your porch, shoot bearings, plot them, see if the lines cross where you're actually standing.
Thanks, Jason