Cornwall - We've got a huge wall of green between us and sprawl marching north from New York City - more than 2 million acres. The Hudson Highlands stretch from east-central Pennsylvania up through northern New Jersey. They cross the Hudson River at Cornwall and spread all the way to Connecticut.

Even parts of this mammoth green belt are in danger of inappropriate development, says an in-depth report on the Highlands released yesterday by the U.S. Forest Service that surveyed changes in the region over the past 10 years. The report used satellite mapping, aerial photographs and U.S. Census data.

Noting that "development in these sensitive areas increased dramatically between 1984 and 2000," the 183-page report warns that Orange County privately owned, raw land near streams and wetlands is especially vulnerable to development.

Much of the 500,000 acres of the Highlands in New York are already protected, such as the 16,000 acres of the U.S. Military Academy at West Point, or the 4,000 acres of Black Rock Forest, where 10-12 coyotes roam any given day.

But major "conservation gaps" of unprotected land exist in Orange County, said Richard Lathrop, a Rutgers University scientist and report co-author. Notable, he said, was the Town of Tuxedo, which ranks high in the Highlands' parcels rich in wildlife habitat, potential recreation areas and open space.

The report didn't get into community-by-community figures but gave this overview: the New York section, including Rockland County, grew to 628,743 people in 2000 from 565,067 in 1990, which shows up as a northward-creeping pattern of development on the satellite map.

Predicting a 48 percent population increase in the near future under current zoning and land-use laws, the report sees 80 percent of the Highlands at risk.

Just 20 percent of the Highlands are publicly or privately protected. The report didn't say how much of that is in Orange County.

This latest evidence that sprawl threatens some of the land that also helps recharge water supplies comes as county officials plan a report of their own on traffic and land use in Orange's fast growing southern section, which includes Tuxedo.

New Orange County Planning Commissioner David Church, who takes office next month, saw the Forest Service report reinforcing the need for communities "to cooperate for rational land use." A similar, 1992 report on the Highlands spurred the creation of 18,000-acre Sterling Forest State Park.

Orange County Land Trust Executive Director John Gebhards said his group is trying to obtain about 2,500 additional acres to add to Sterling Forest, which cost a coalition of environmentalists, charities and government officials more than $55 million to assemble in 1998.

Yesterday's report recommends:

• Linking pedestrian and cycling access to the 150-mile Highlands Trail connecting the Hudson and Delaware rivers.
• Promoting collaborative decision-making.
• Educating the public about the Highlands, which are too often seen as just Storm King Mountain or Sterling Forest, which are just two of the wild places in a mosaic of farms, forests, reservoirs and streams that make up the Highlands.

"The main point is there are critical resources that we feel are important to protect and this report helps identify where they are." said Martina Hoppe, a Forest Service regional planner.

Copies of the report are available from the Forest Service at 1547 County Route 565, Sussex, NJ 07461 or e-mailing a request to NA_HighlandsStudy@fs.fed.us. The report is online at www.fs.fed.us/na/highlands