PORTLAND - Oregon has been a national leader for more than 30 years in fighting urban sprawl and protecting forests and farmland from turning into houses as the population grows.

And for all those years, there have been property owners who chafed at the idea that they couldn't use their land as they saw fit.

That has all changed with passage Tuesday of Measure 37, which allows landowners to make claims against governments when land-use regulations reduce the value of their property.

The measure also gives governments the option of waiving regulations instead of paying compensation, which would create a patchwork of development regulation around the state based on when a piece of property was acquired.

The nuts and bolts remain to be worked out, but it is clear that owners of millions of acres of family farms and small timberlands near fast-growing cities are at ground zero.

One of them is Dorothy English, 91, who has owned property on the outskirts of Portland since 1953 and was shocked to learn in 1974 that the Land Conservation and Development Act, enacted one year before, barred her from breaking her 40 acres into more than three parcels.

"After 31 years of having this around my neck, you bet I'm going to make a claim," said English. "They destroyed my retirement and our lives, really," she added. "That's stealing. I don't know any other name for it."

No one has figured out just how much land in Oregon would be eligible, because it depends on when the owner acquired it and when the regulation they object to went into effect.

In all, 5.5 million acres are in farm zones in the state and 10.5 million acres in forest zones, accounting for 94 percent of the private land in the state, said Ronald Eber, farm and forest land specialist at the Department of Land Conservation and Development. Another 900,000 acres are in rural residential zones.

Of that, 4.4 million acres are in small woodlands averaging about 70 acres, much of which is near cities where it could be developed for residential property, said Mike Gaudern, executive director of the Oregon Small Woodlands Association. And many of the owners have chafed under state land use rules barring them from building homes on their timberlands.

Owners of industrial forest lands are unlikely to be making claims, either to develop their lands or waive environmental restrictions, said Ray Wilkeson of the Oregon Forest Industries Council. Council members support the Oregon Forest Practices Act, and most of these lands are too far from growing cities to provide much potential for residential development.

"There is a potential there for a substantial number of claims," said Lane Shetterly, director of the Department of Land Conservation and Development. "We're sure not overreacting and proclaiming the end of land use planning in Oregon, but we will surely see some changes on the ground if the measure is implemented as approved."

Jackson County in Southern Oregon, one of the fastest-growing areas of the state, tried to get an idea how many claims it might face, and soon realized that while there are many large parcels of farm and forest land in longtime ownerships, it would be complicated and costly to figure out exactly how much, said Paul Korbulic, county director of parks, roads and planning.

"We're in a position of waiting to see," he said.

Because this marks the second time voters approved a similar measure, the Legislature is unlikely to try to change it significantly. But it will be up to the Legislature to develop procedures for implementing it.

Gov. Ted Kulongoski said the state is not in a good position financially to help counties. State estimates have put state and local administrative costs as high as $344 million.

"I think the Legislature may have to step in and pass some curative legislation to make it work. We did this with property tax limits," passed by voters in the 1990s. "This is something we can do."

David Hunnicutt of Oregonians in Action, which put Measure 37 on the ballot, said he thinks alternatives sources of money could be found to pay claims. For example, easing development restrictions would increase the value of some properties, resulting in higher property taxes. Those could be put in a special fund to pay claims.