Younger Lagoon Reserve, Coastal reserve in Santa Cruz, US

Younger Lagoon Reserve is a 72-acre University of California Natural Reserve System site on the northern shore of Monterey Bay, next to Long Marine Laboratory. It holds a seasonal Y-shaped lagoon, a pocket beach, wetlands, coastal prairie, a sea stack, sea caves and tidepools. The lagoon drains within hours when winter storms erode the sandy berm at its mouth.

The reserve was established in 1972 when Donald and Marion Younger donated their family ranch land to the University of California. This gift created the foundation for what became a lasting research and conservation area.

The reserve lies within the traditional territory of the Awaswas-speaking Uypi, part of the broader Ohlone-speaking region of Monterey Bay. The land was later ranched by the Younger family for over a century before the 1972 donation. Visitors can see the coastal prairie and lagoon that these successive uses shaped.

The reserve is owned by the University of California and managed for teaching and research, so access is arranged rather than open; check with the UC Natural Reserve System or Long Marine Laboratory before visiting. The seasonal lagoon drains within hours once winter storms erode the sandy berm at its mouth, so the shoreline changes through the year.

The Y-shaped lagoon is seasonal: winter and spring rains fill it until storms erode the sandy berm at its mouth, and the whole lagoon drains into Monterey Bay within a few hours. Ocean water then refills it until waves rebuild the berm and runoff freshens the water again.