Oregon has run a statewide land-use program for fifty years, and two pieces of it do most of the work.
Exclusive Farm Use zoning is a county zoning designation that says a piece of ground is for farming. Houses, shops, and subdivisions are sharply limited on it. A landowner cannot simply decide to put twelve homes on a hayfield because the zoning does not allow it.
An urban growth boundary is a line drawn around each city. Inside the line, cities plan for streets, sewer, and development. Outside it, they generally do not extend services, which is what keeps subdivisions from marching into farm country. Moving the line is a public process, not a private decision.
Together, those two tools mean most farmland here stays zoned for farming. That is genuinely rare in the United States, and it is why land trusts in Oregon often aim their easements at habitat and river corridors instead — the farmland protection problem is largely handled.
Here is the turn. Zoning governs use. It does not govern ownership, and it does not govern price. A field can be permanently zoned for agriculture and still sell for more than any working farmer can service — to an investor, a vineyard buyer, or someone who wants a view. The land stays farmland. Who farms it, and whether they can afford to, is an open question.
Succession is where that question comes due. Roughly two-thirds of Oregon’s farmland is expected to change hands in the next twenty years, and most of it has no plan behind it.
Source: Oregon Agricultural Trust estimate.