Elkhorn Slough National Estuarine Research Reserve

When is the best time to visit Elkhorn Slough National Estuarine Research Reserve?

By typical weather, the best months for a day outdoors here are June, July, and August.

The warmest month is August, with average highs near 77°F (25°C); the coolest is December, near 57°F (14°C).

December is the wettest month, with about 4.5 in (114 mm) of precipitation in a typical December.

Typical weather, 25-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2025). Data from NASA Langley Research Center POWER Project (CC BY 4.0)

Official facts

Adjacent protected waters: Elkhorn Slough State Marine Reserve. State Marine Reserve, No Take, 7 km².

Protected waters: 5.9 km². None of it is no-take.

Boating: Vessel use prohibited; anchoring prohibited.

Fishing: No Site Restrictions.

Conservation focus: Natural Heritage. Protects the whole ecosystem. Site-Specific Management Plan.

IUCN category: IV (Habitat or species management area).

Protection level: Uniform Multiple Use.

Marine protection: National Estuarine Research Reserve. Listed as "Elkhorn Slough National Estuarine Research Reserve" in NOAA's Marine Protected Areas Inventory, managed by California Department of Fish and Wildlife & National Oceanic and Atmospheric Administration, established 1979.

Public access: Open access.

Protected area: 1,703 acres (689 ha).

Designation: State Conservation Area. Listed as "Elkhorn Slough Ecological Reserve" in the Protected Areas Database of the United States. Protection: managed for biodiversity (GAP 2). IUCN category V.

Established: 1980.

Managed by: California Department of Fish and Wildlife.

Critical habitat: California red-legged frog (threatened). Rana draytonii. Endangered Species Act critical habitat (final rule published 2010-03-17, 75 FR 12816), mapped at or near this park.

NOAA Marine Protected Areas Center (Office of National Marine Sanctuaries) with the US Department of the Interior, MPA Inventory 2023 · U.S. Geological Survey (USGS) Gap Analysis Project (GAP), 2025, Protected Areas Database of the United States (PAD-US) 4.1 · U.S. Fish and Wildlife Service, Endangered Species Act critical habitat (FWS HQ ES Critical Habitat)

History

Opened

1982

Owned by

California Department of Fish and Wildlife

• Park opened