The hook
The old bluff-top road between Crockett and Martinez was too landslide-prone to keep as a through road — so the middle became a car-free ribbon above the strait, and the whole thing became the East Bay's best slow mile.
01Why it's worth it
This is the atlas's first route pin: the experience is the line, not a point on it. From Crockett the drive climbs along the Carquinez Strait's bluffs — tankers below, wharf-house history along the water, Port Costa's dead-end time capsule at the midpoint — and where slides closed the road to cars, the county paved it for bikes and walkers instead (the "George Miller Trail" section). Riding the closed stretch at golden hour, strait on one side and empty grass hills on the other, is the concentrated version of everything this corridor does. The endpoints book-end it properly: Crockett's C&H-company-town streets on one side, Martinez's John Muir house on the other, Port Costa's saloon in the middle.
02How to experience it
Drive it Crockett → Port Costa (open to cars), then park and walk or ride the gated middle section toward Martinez; bikes do the full line one-way. Combine with the Port Costa evening — this route is the reason to arrive the pretty way.