Freshwater Lagoon

Geology

Freshwater Lagoon sits within Humboldt Lagoons State Park on the coast of Humboldt County, California. It is the northernmost and smallest of the park’s three similar lagoons. The lagoon lies between Trinidad to the south and Orick near the mouth of Redwood Creek to the north. These lagoons are shallow bays formed behind sandy bars that separate them from the Pacific Ocean, created by wave action between rocky headlands.

They serve as resting spots for migratory waterfowl traveling the Pacific Flyway, connecting Lake Earl about 40 miles north and Humboldt Bay about 30 miles south. The lagoon’s surrounding hills are made of undivided pre-Cretaceous metasedimentary rock. Tectonic activity along the Cascadia subduction zone has caused sea level changes every few centuries, alternating the plain between freshwater wetlands or Sitka spruce forests after uplift and salt marsh or shellfish beds after subsidence.

The lagoon’s small catchment basin has built a durable sand bar that recent storms have not breached; rain usually soaks through it without forming a surface channel.

Recreation

U.S. Route 101 traverses the coastal sand bar between Freshwater Lagoon and the Pacific Ocean. Convenient parking on the sand bar adjacent to the highway has made the lagoon a popular scenic rest area for motorists in Humboldt Lagoons State Park. There is also a Redwood National and State Parks visitor center near the north end of the lagoon.