This is a spot that "you'd never know about if it wasn't for Geocaching or cycling!" This spring has been maintained for decades by local cyclists, for local cyclists. It's just below the 3 mile marker, at about 3200 foot elevation. (You did notice the large painted markers, showing mileage from the summit, didn't you?)
I doubt there are many people who would see or hear this when zipping by in their vehicle, but on a bike it's obvious. Anyway, stop and enjoy the spot.