Where to cut wooden board thickness into half?

Oh, lord.

Home Depot won't even do a measured cut, like cut an 8 foot board to two 4 foot boards. They will not accept the responsibility.

What you want requires a special saw and major machinery. You might try googling lumber yards, reclaimed lumber, and/or custom millwork. I suspect that IF you're lucky enough to find someone to do this for you, it will need to be shipped across the country. The size precludes everything except a special truck delivery that will start around $200. It's a nice wide board (the depth is 1.5), probably old growth, but it may not be worth it.

Mike's Lumber, 88th and bway.

I don't think even Norm Abram has a saw in his shop to make that cut. I would be absolutely shocked if anybody in Manhattan had that saw either.

You basically need to find somebody with a giant, highly accurate band saw. needsadvice is right on -- people who deal with reclaimed lumber will be your best bet.

It sounds like a nightmare of a cut to make though, even with precision machinery. If the board isn't perfectly straight and true in every dimension, it's easy to imagine a scenario where the thickness of the two boards isn't identical afterward. Also, you need to account for the saw kerf; the resulting boards are going to be thinner than 3/4" since the saw blade is going to consume some of the material.

"Board" may not be quite the word. It sounds as if it's a piece of countertop made out of two .75" sheets glued together.

Anyway, if it's a single piece of wood, it's extremely valuable and you should sell it to a furniture-maker. Then have somebody make you something out of two sheets of .75" plywood, and veneer it.

If it's really a bunch of narrow planks joined edgewise with splines, then that miracle saw-cut would go right through the splines and the whole thing would fall apart.

If course, you aren't going to have two pieces .75" thick. The saw blade will eat some of it (that saw dust comes from somewhere. More like max of 7/16" per piece

Thanks for all the suggestions! I actually just need one board (I can forgo the second piece). Does it make a difference?

And I admit I used the wrong word. It is a piece of countertop. It is a bunch of narrow planks joined edgewise. But I am not sure if they are joined by splines or glue.

Is this a butcher block? Regardless, if you really only need one piece, you don't want to saw the thing in half, but plane the faces so all are perfectly flat and level. Any millwork shop will have a power planer. But, 26" is a wide planer -- someone may need to cut the board in half and re-join the board once at your desired thickness.

In the end, I am beginning to wonder if your project is going to cost more than this piece, unless there is something unique about the wood.

There is nothing unique about the wood. What I am trying to achieve is replacing a desk. Not sure where to get it custom made. I don't mind using melamine/laminate (the cheap kind), I just don't know where to get it custom made.