The hook
The city of Arcata treats its sewage by running it through a marsh, and that marsh is now one of the best places to watch birds on the whole North Coast.
01Why it's worth it
In the 1970s, rather than pipe its wastewater off to a big regional plant, Arcata did something radically simple: it built a chain of ponds and constructed wetlands and let nature finish the job, filtering the town's sewage through marsh plants until what reaches Humboldt Bay comes out clean. The result, the Arcata Marsh and Wildlife Sanctuary, is 307 acres of freshwater and salt marsh, sloughs, and mudflats laced with five miles of trail, and because it sits on the Pacific Flyway it has become one of the great birding spots in Northern California, with more than 327 species recorded. It's the rare piece of civic infrastructure people genuinely love to walk: a working sewage plant that doubles as a nature preserve, and the interpretive center lays out the whole clever trick. Bring binoculars.
02How to experience it
The marsh is at the north end of Humboldt Bay in Arcata, off Highway 101, about five hours from the Bay. It's free and open dawn to dusk, with flat, easy trails and an interpretive center. Early morning is best for the birds. It pairs naturally with Ferndale and the redwood parks for a North Coast day.