Cosumnes River Preserve History

The Cosumnes River Preserve is one of California’s most treasured natural landscapes. The preserve protects over 50,000 acres of wetlands, riparian forests, oak woodlands, and grasslands along the Cosumnes River, the last free-flowing river in the Central Valley. Unlike other rivers that are dammed or diverted, the Cosumnes still follows its natural seasonal rhythms, spilling over its banks in the winter and spring to flood the surrounding plains. These floodwaters create rich habitat for fish, waterfowl, and countless other species, while also replenishing groundwater and supporting healthy farmland.

In 1987, local citizens, conservation groups, and public agencies came together to establish the Cosumnes River Preserve. Their vision was to protect and restore this rare landscape where the river still runs free, while also providing a place for people to connect with nature. Today, the preserve is a living example of how conservation and community can work hand in hand.

As you explore, you’ll see migrating sandhill cranes in winter, tall cottonwood forests in summer, and seasonal wetlands teeming with life year-round. Each trail, slough, and grove tells a story of resilience—both of the river itself and of the people committed to safeguarding it for generations to come.