The palette
This is a rare sheet where green does more than water: the creek is only a thread, but the wooded canyons draw the whole landscape around the town. Choose a green with enough depth to carry those long trails, and keep the background close to the paper, because the blank between them is where the rock is; give that blank a strong colour and it will read as something else. Water needs an ink strong enough for a thin line. The streets are few and scattered: a mid-tone line keeps each pocket readable, with the darkest ink kept for the two highways.