Lake Cleone Estuary, located in MacKerricher State Park along California's Mendocino Coast, is a small but ecologically rich coastal lagoon. The lake is modified by a human-made dam, though it still functions as a dynamic system influenced by seasonal rainfall and coastal conditions. Covering approximately 30 acres, the estuary connects to the Pacific Ocean during high flows, allowing for tidal exchange and supporting a mix of freshwater and brackish habitats.

The surrounding coastal climate, characterized by cool, foggy summers and mild, rainy winters, shapes the estuary's conditions and the species it supports. Lake Cleone provides critical habitat for fish, birds, and amphibians, while its wetlands and riparian zones filter water and reduce erosion. Ongoing conservation efforts aim to protect this sensitive ecosystem, which serves as an accessible site for both recreation and environmental education.