Firemen in San Francisco have a unique problem: low old-style power lines are a dangerous issue when swinging around metal ladders, and light fiberglass ladders aren’t sturdy enough to stand up to fire department service. So, the San Francisco fire department has its own wooden ladder-making shop which supplies San Fran’s Finest with the means to climb as high as they need without adding further risk to the firefighters’ lives.
When you’ve got five options to map out, what’s the obvious format? Make it look like a hand:
BigThink.com has more information on what each finger means, but not being from California means that I don’t understand the layout, and it just looks like a kinda diseased hand with labels all over it. I’ll take their word for it that I’d enjoy spending my leisure time tracing these fingers through the Santa Cruz countryside.