An hour after the late afternoon high tide had peaked and the sun was dropping, my girlfriend Holly and I decided to make a run for it. Our four-mile dash was along Northern California’s Lost Coast—in a particularly gnarly section of it generally considered impassable. Stuffed with craggy rock outcroppings, gritty black sand beaches, and a mess of rushing creeks converging into thunderous, unruly surf, this far-flung shoreline was fast living up to its name. Along Northern Califor...