Black_Diamond, I am often impressed with your contributions, input and corrections to map data, especially in Santa Cruz County.  However, I can't figure out what you are tying to do here.  (Align park data and road data, which I am in this area as well, and have been for many years...my explanations above go some distance to do so).

In my (15 years in OSM, as a professional cartographer, computer / data scientist, software engineer...) experience, these things tend to work themselves out over time.  (As I say above).  In my opinion (and I could be wrong), CPAD data (meaning "getting better input data that better aligns the road, Smith Grade) is required.  I could be wrong.

I wrote our California/Using CPAD Data wiki, I entered connecting trails (many years ago using excellent GPS tracking equipment), including Woodcutter's Trail and I've pondered long and hard about the (relatively slight, truth be told) mismatches between Smith Grade and "park alignment with the road of Smith Grade" data here, and here is my conclusion:  Smith Grade is about as correct as it can be given aerial data (which, given the tree cover, isn't great), and the park boundary data have some "catching up" to do.  Can I prove that?  No, but the "wandering" the boundary data do given the VISIBLE road data do (tend to) support this assertion.

If you can improve something with definitive data, great:  I welcome improvements to OSM.  That might happen by submitting to GreenInfo (CPAD publisher) that they assert to State Parks that these Smith Grade data are pretty messy.

And hey, "this happens."  Look, for example at Hwy 236 and Big Basin, where similar "wanderings" (between road and park boundaries) take place.