🏆🏆 San Joaquin River Oasis — River recreation on the Merced River in the heart of the Central Valley
George J. Hatfield State Recreation Area provides river recreation along the Merced River near the town of Hilmar in the San Joaquin Valley. The park offers fishing, swimming (seasonal), picnicking, and camping among mature valley oaks along the river — a welcome green oasis in the agriculturally intensive Central Valley. The Merced River here is slower and warmer than its mountain reaches near Yosemite, providing relaxing river recreation.
Visitor Information
| Detail | Information |
|---|---|
| Location | Hilmar, CA (San Joaquin Valley) |
| Entry Fee | $8 per vehicle |
| River | Merced River |
| Activities | Fishing, swimming, camping, picnicking |
Frequently Asked Questions
Is swimming safe?
Swimming is seasonal and conditions vary with water flow. The Merced River can have strong currents during spring snowmelt. Check current conditions before swimming.
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Do salmon really swim from the ocean to Yosemite?
Historically, Chinook salmon swam from the Pacific Ocean up the San Joaquin, Merced, and other rivers into the Sierra Nevada foothills. Dams now block their passage — salmon can no longer reach Yosemite. But fall-run Chinook still spawn in the lower Merced River, making Hatfield one of the few places to witness this ancient migration in the Central Valley.
Make it a road trip: Pair a visit with Great Valley Grasslands State Park (a short drive away) or Dos Rios State Park (within about an hour’s drive).
Camping reservations: Book campsites and cabins for California state parks online at reservecalifornia.com.
🎣 Visit George J. Hatfield SRA
Merced River recreation — fishing, camping, and valley oak shade in the Central Valley.
About George J. Hatfield SRA
George J. Hatfield State Recreation Area sits at the confluence of the Merced and San Joaquin Rivers — one of the few remaining natural river confluences in California’s heavily engineered waterway system. Valley oak riparian woodland and river access in the Central Valley.
Things to Do
Fishing for catfish, bass, and seasonal salmon, camping (30 riverside sites), summer swimming, and birdwatching for wood ducks, great blue herons, and Swainson’s hawks.
Insider Tips
Central Valley oasis: Hatfield SRA provides riverside recreation along the Merced River near the San Joaquin Valley floor. Pro tip: The Merced River flows directly from Yosemite Valley — the same water that cascades over Yosemite Falls and through the valley passes by this park. Salmon connection: Fall-run Chinook salmon still ascend the Merced River to spawn — one of the last salmon runs in the Central Valley.
Best Time to Visit
Spring: River flows peak with Sierra snowmelt. Fall: Salmon run (October-November). Summer: Swimming and tubing — temperatures exceed 100°F. Winter: Quiet fishing and birding.
Wildlife & Nature
George J. Hatfield SRA — an alternate listing for the Merced River recreation area — provides camping and fishing along the river. The riparian corridor of valley oaks, willows, and cottonwoods supports yellow-billed magpies (endemic to California’s Central Valley), red-shouldered hawks, and Cooper’s hawks. Western pond turtles sun on logs.
Nearby Attractions
Yosemite National Park — accessible via Highway 140 through Merced — has Half Dome, El Capitan, and Yosemite Falls. Merced — the nearest city — has UC Merced. Castle Air Museum — near Atwater — has historic military aircraft.
