THE ROOT OF EVERYTHING HERE
The Edge Run.
Before it is terrain and before it is a river, it is this: the left edge of rule 30, in the frame that travels with it. The lit band along the edge is the run of ones, and its depth at each generation — run(g) — is exactly what the ranges, the rivers and the villages are built from. Read off the picture, it agrees with the law: runAt(g) predicts it without evolving anything.
Rule 30, edge frame
Each row is one generation; the gold bits are the run of ones at the edge.
run(g) and the ruler beneath it
Top: the run at each generation, read from the band and from the law (they coincide). Bottom: v₂(g+1), the number of trailing zeros — divisible generations stand tallest.
Where it lands in the worlds
In the original Atlas world a north–south range stands at every column x in proportion to run(x); on Planet One a ridge of scale v stands where the cell index is k·2^v − 1 — the same counting. Pick a generation above and step in.
Stand at column g in the Atlas →See the profile on Ruler Range →