19th century US plat map iconography

[KMAlexander]

I tend to notice *s near water courses, sometimes in the presence of an interrupted road, or a bumped road, or neither, sometimes major water courses, sometimes very minor ones.

Hi! I work extensively with old maps (usually from the 17th and 18th century) for my brush sets.

In the example you provided above, I'd wager those spoked wheels are marking the presence of water mills. That's been a fairly common symbol for a few hundred years.