Divide
Field guide/Philosophy

Cairns, routes, divisions: how Divide thinks about a trip

MM
Malcolm McSwain
Updated Jul 2026 · 7 min read

Every planning tool has a theory of what a trip is. Most of them think a trip is a line on a map. Divide thinks a trip is a sequence of commitments — and the whole tool falls out of that one disagreement.

Three ideas are enough to describe any trip I have ever planned, from a two-night car camp to a three-week multi-sport road trip. Where you will be. How you get between. And where the plan is allowed to change. In Divide those are cairns, routes, and divisions.

Cairns: where you will be

A cairn is a place you commit to being — a trailhead, a camp, a put-in, a summit, a diner in Bishop. On trail, a cairn is a stack of rocks that says someone stood here on purpose. In the plan, it does the same work. It is not a suggestion or a region of interest; it is a claim: on day 3 we sleep at Merced Lake.

That claim is what everything else attaches to. A permit belongs to the cairn that needs it. A forecast belongs to the cairn's coordinates on the cairn's date — not to the nearest town at a different elevation. Mileage and gain describe the work of reaching it. A plan made of cairns can be checked; a highlighted line on a map cannot.

Routes: how you get between

A route is the leg between two cairns, and it is where trips actually fail. Nobody blows a trip standing at a campsite. Trips blow up in the space between — the drive that was five hours, not three; the “six easy miles” with 3,100 ft of gain; the paddle that a headwind turned into an afternoon.

So a route carries a mode — drive, hike, bike, ski, paddle, transit — and an honest budget: distance, duration, gain. Change the mode and the numbers change with it. A plan that has budgeted every leg knows what time you arrive everywhere. A plan that hasn't is a list of wishes in chronological order.

Divisions: where the plan is allowed to change

The name Divide comes from the third idea. A divide is where watersheds split — where one more step commits you to a different valley. Every real trip has these points, whether you plan them or not: the lottery result, the storm forecast, the group that's slower than hoped.

A division makes the fork explicit. It lives on a route — a specific leg where the trip could go two ways — and it has three parts: a condition (“Cables permit drawn?”), and two named branches, each with its own sequence of cairns. Plan A and Plan B are both real plans, built in advance, with their own camps and their own paperwork.

The shape of a trip in Divide
D1Tuolumne Meadows trailheadcairn
hike · 6.5 mi · +1,200 ft
D2Cathedral Lakes campcairn
DIVISION · Cables permit drawn?
Plan A — permit drawn
Half Dome cables → Little Yosemite
Plan B — no permit
Clouds Rest → Sunrise Lakes camp

How they fit together

The three ideas nest. Cairns are the nouns. Routes are the verbs connecting them. Divisions are the conditionals — the only places the sequence is allowed to branch. String them across days and you have the whole trip: a trunk of commitments, with a small number of deliberate forks.

The discipline matters more than the vocabulary. If something is a cairn, it has a place, a date, and its paperwork attached. If something is a route, it has a mode and a time budget. If the plan might change somewhere, that somewhere is a division with a condition and two finished branches — not a shrug. A trip written this way can be handed to a stranger, or to a version of you that is tired, cold, and behind schedule. That is the version of you the plan is for.

Go deeper
Each idea gets its own essay — cairns, routes, divisions — and the capstone puts them to work on risk.
Start with cairns
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