Finished the road blog on the Marin Headlands:
http://surewhynotnow.blogspot.com/2017/11/november-bay-trip-part-5-marin-headlands.html
I actually took part of Sir Francis Drake Boulevard to reach the Headlands. I don't know if there will ever be another opportunity to talk about unbuilt CA 251 so I mentioned the proposed alignment it was intended to use.
Prior to the commissioning of I-580 over the former CA 17 circa 1986 (coincidental with the signing of I-880), the proposed but never adopted freeway from San Rafael to Point Reyes Station was designated CA 17; when the Interstate designation subsumed 17 the CA 251 designation replaced it -- a functional extension of the historic 251 alignment from CA 17 (I-580) at the west end of the Richmond-San Rafael Bridge at San Quentin west more or less along the southernmost section of Sir Francis Drake Blvd. to US 101 at the north end of Corte Madera. That unbuilt corridor extended west along S.F. Drake through Fairfax all the way to just short of that boulevard's west turn toward CA 1. Originally it was slated to head north to join another unbuilt roadway -- the extension of CA 37 west from Novato; CA 17 turned left on what was the CA 37 trajectory to end at CA 1 just north of the town of Point Reyes Station. When the designation was changed to 251, 37 was extended west to CA 1 while 251 simply ended at the 37 alignment. All of that is a moot point; between the Coastal Commission, which has jurisdiction over the area, and Marin County NIMBY's, neither corridor will ever see the light of day. West Marin folks definitely value their privacy and prize their relative isolation; this was in evidence back in 1976 when I was staying with a friend in Bolinas and working "over the hill" in Mill Valley. Bolinas was (and still is) a unique and iconoclastic place (with the only
quasi-municipal clothing-optional beach in the state); they'd rather no one know they're there, so every time Caltrans gets around to putting up a sign on CA 1 at the approach road, someone comes out from the town and simply removes it. So there's a signpost (or even a pair of them) without a sign on CA 1 at the top of Bolinas Bay; the location remains "signless" until someone in District 4 gets a bug up their ass about it and commissions another sign; and then the process simply repeats itself. It's like a Keystone Kops adventure -- CHP historically will platoon a vehicle to watch the sign right after it's replaced; the townsperson charged with removing it simply waits until the cop leaves at the end of his/her shift and makes off with the sign. No agency wants to pay for continually monitoring the situation, so once a sign is no longer there, that condition remains static for often a couple of years. If no one's guessed, Bolinas is one of the places that, in the early '70's, became a sort of refuge for disaffected "hippies" and the like (when Grace Slick & the late Paul Kantner were still a couple with their young daughter, they had a big house overlooking the beach in central Bolinas -- I attended a few rather memorable parties there!); unless something particularly egregious occurs, county and state officials tend to leave them to their own devices.