Potter's vision was grand in the way that only early-twentieth-century American ambition could be. Getting to Bayocean meant traveling overland to Tillamook and then crossing the bay by boat, the final leg an often terrifying passage through the unprotected mouth where Pacific swells met tidal currents. Visitors arrived windblown, sometimes seasick, and stepped onto a spit that stretched barely a quarter mile across at its widest. Yet Potter had built an entire resort town there: the natatorium alone was a marvel, an enclosed pool fed by ocean water, ringed by viewing galleries. Lots sold briskly. Families built cottages. For a decade, Bayocean thrived with the buzzing optimism of a community certain that progress and proximity to the sea were the same thing.

Bayocean's undoing began with an act of good intentions. Residents, tired of the rough crossing into Tillamook Bay, petitioned the Army Corps of Engineers for a jetty to calm the entrance. The Corps studied the site and recommended two jetties, one on each side of the bay mouth, at a cost of $2.2 million -- half to be raised locally. The community could afford only one. A single jetty was built on the north side of the entrance in 1917, and it worked exactly as designed: it calmed the north channel. But it also disrupted the natural sediment transport that had maintained the spit, redirecting the ocean's energy into the shoreline where Bayocean sat. The currents that had built and maintained the peninsula for millennia now began to dismantle it. Sand that once replenished the beach moved elsewhere. The shoreline started retreating, slowly at first, then with gathering speed.

The natatorium went first. Erosion undercut its foundations, and the great pool -- the pride of Bayocean -- collapsed into the surf. Then the hotel. Then the cottages, one by one, as the ocean chewed westward across the spit. Residents watched their homes slide down eroding bluffs and break apart in the waves. Some moved their houses inland, buying time, but on a spit only a few hundred yards wide there was nowhere to retreat to for long. The post office closed in 1953, a quiet official acknowledgment that the community no longer existed in any meaningful sense. By then, most buildings were gone -- swallowed, toppled, or simply abandoned. In 1956, what little remained was demolished during a reclamation and dike-building project. The town that T. I. Potter had once advertised with full-page spreads in Sunset Magazine had been erased.

Today, Bayocean Peninsula Park occupies the spit where the resort once stood. A trail loops through dune grass and coastal scrub along the bay side and returns on the beach, a quiet walk with no trace of the streets and sidewalks that once ran here. From March through September, hikers are restricted to wet sand near the waterline to protect the nesting grounds of the western snowy plover, a threatened shorebird that has reclaimed the dunes Potter once platted into building lots. The second jetty was eventually built in 1971, and the spit has stabilized somewhat, though it remains a dynamic place, shaped and reshaped by tides and storms. Bayocean is sometimes called Oregon's Atlantis, and the comparison fits -- not because of any mythic grandeur, but because of the essential human miscalculation at its core: the belief that you can build permanently on sand and command the ocean to hold still.