Every Lake
O'Neill Forebay
A pumping station's holding pond, finished in 1967, now chased by windsurfers most afternoons.
- 7 ft · first step
- 13 ft
- 20 ft
- 26 ft
- 33 ft
- 39 ft · bottom
About O'Neill Forebay
O'Neill Forebay was completed in 1967 as part of California's State Water Project, built jointly with the federal Central Valley Project's San Luis Unit. It sits below San Luis Reservoir near Los Banos, in Merced County, and functions as a regulating pool: water arrives from the Delta-Mendota Canal and the California Aqueduct, then gets pumped uphill into San Luis Reservoir for storage before being released back down through the O'Neill Pumping-Generating Plant. The forebay's job is timing, not storage — it buffers flow between two systems that don't run on the same schedule.
The surrounding land is flat irrigated farm country along the Highway 152 corridor between Los Banos and Santa Nella. Afternoon winds funnel through the Pacheco Pass gap with enough consistency that the forebay draws windsurfers and kiteboarders most days from spring through fall, alongside anglers after striped bass and Chinook salmon that move through the pumping plant. It sits within San Luis Reservoir State Recreation Area, shallower and more elongated than its neighboring reservoir, its shape following the canal alignment it was built to serve rather than a natural valley.
- 2 shore towns named, with a star on each
- 108 roads engraved around the shore, 5 of them labeled
- 6 depth layers, each step engraved with its depth in feet
- Compass rose, title block with coordinates, max depth and area; keyhole hanger on the back
Turn it in your hands
Live 3D of the actual cut files — drag to orbit, pinch to zoom. Every road you see is engraved on the real thing.
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O'Neill Forebay depth chart, in wood
This is a O'Neill Forebay depth chart you can hang: 6 stacked layers of birch, each one a depth contour — 7 ft, 13 ft, 20 ft, 26 ft, 33 ft and deeper, down to the deepest hole at about 39 ft. The lake covers about 3.5 square miles, and 108 shore roads are engraved around it. The shape of the bottom is the real one from published soundings, so anglers recognise their drop-offs and points.
A O'Neill Forebay map for the wall — or a gift
Most of these go to a cabin wall, a lake house entry, or a home office; a lot are gifts — the family that has been on O'Neill Forebay for three generations, the retirement move, the first boat. The 12-inch is the desk-and-shelf size; the 24- and 30-inch boards read across a room. Add a line under the title and star your place on the shore, and it becomes the map of your O'Neill Forebay.
O'Neill Forebay map — the details
How big is the map?
Four sizes: 12, 17, 24 and 30 inches on the long side, from $149. Every size is cut from the same depth data of O'Neill Forebay; the bigger boards carry more shoreline roads and place names.
Is it made from real depth data?
Yes. O'Neill Forebay is cut layer by layer from published bathymetric soundings — each layer of birch is a depth contour, so the shape of the bottom is the real one, not decorative.
Can I add my own place on it?
Yes. At checkout you can add a line under the title (a family name, a cabin name, a year) and star the spot on the shore that matters to you.
How long does it take?
Made to order in Waterford, Pennsylvania and shipped in 7–10 days; shipping is free in the lower 48.
Can you make a lake that isn't listed?
Any lake in the United States — we hold depth data for 104,419 of them. Search for yours; if it isn't built yet we build it when you order.
- 6 depth layers down to 39 ft
- 3.5 square miles of water
- 108 shore roads engraved, 5 named
- Title block, compass rose and depth markers
- Birch plywood, keyhole hanger, made in Waterford, PA
