I stopped here on a run one day and was surprised that there was not a cache. I decided to place my first hide here.
Frenchman's Road (which lines the east side of the park), Frenchman's Lake (mentioned in the plaque near GZ), and Frenchman's Tower (on Old Page Mill Road) all refer to the frenchman Paulin Caperon, who went by the name Peter Coutts back in the late 1800s. There's also a road named Peter Coutts in the area.
While you're here, have a look around the park. There's a bridge to nowhere which I find particularly interesting, which was likely constructed by Caperon as well.