American sycamore trees tower over a largely untouched 5-acre plot of land tucked away in Oyster Bay Cove on bucolic Yellow Cote Road.

Baltimore orioles and songbirds flutter across the property. Its acquisition, environmentalists say, is a critical step toward expanding the existing preserve that is home to dozens of plant and animal species.

The North Shore Land Alliance, a Mill Neck-based nonprofit, is raising funds in the hopes of purchasing the land from the Pulling family, who has owned it for more than a century. Lisa Ott, president of the Land Alliance, said the conservation group has raised about $610,000 toward a purchase, which is likely to total $1.5 million. The nonprofit would buy the stretch of woodlands and open fields, which are in a special groundwater protection area. Development is not recommended in these environmentally sensitive areas to allow for groundwater recharge, a process that draws the water back into the aquifers and helps replenish the water supply.

On Long Island, there are nine such state-designated regions considered vital to protecting groundwater conditions.

The acquisition “would permanently protect more water," Ott said in an interview. “This is just a place that really deserves protection.”

The North Shore Land Alliance struck a deal with the Pulling family in February. The one-year option gives the nonprofit a year to come up with the funding to buy the land, nonprofit officials said.

“If we can’t conserve it, then they would have to sell it for development,” Ott said.

In addition to the 30 acres of the Nassau County-owned Red Cote Preserve — with its winding paths cutting through meadows and forest — an additional 50 protected acres to the north are separated only by Northern Boulevard. The connectivity of those sites creates a “corridor for wildlife,” said Jane Jackson, the North Shore Land Alliance’s director of stewardship.

Jackson said the 5 acres could support a mix of species, including great-horned owls, screech owls and foxes. By growing the preserve, Jackson said more natural space will be available for people while ensuring "safe passage for wildlife."

In the 2000s, then-Nassau County Executive Tom Suozzi appointed committees to recommend plots of land to be bought with Environmental Bond Act revenue, according to Newsday archives. Parts of the Pulling family property were selected and later purchased in 2008 to help establish Red Cote Preserve.  

Charles Goulding, the mayor of Oyster Bay Cove, said the village "has had a commitment to creating sanctuaries and parkland properties, and we have many residents that want that."

"When possible, I always like to see properties put into sanctuary status," Goulding said, adding that he's open to development when it's sensible. He said the village has enacted stringent building codes that can "add measurable costs" to the price of new development.

Ott said the land alliance, which manages the preserve, would establish a new trail on the property. 

“It looks like time stopped 100 years ago, and you just get such a good feeling being on that land,” Ott said.

In the 1980s, nine Special Groundwater Protection Areas were identified on Long Island, including one where Red Cote Preserve is located, officials said.

Lee Koppelman, the former executive director of the Long Island Regional Planning Board, laid out the threat of development to the environment in a 1992 document known as the "Comprehensive Special Groundwater Protection Area Plan." Koppelman wrote, "the environmental predicament confronting Long Island is that the development potential, including the inescapable modifications to the environment, has and continues to occur more rapidly than our ability to foresee or deal with the ultimate effects of such activities."

Koppelman added that "financially stressed public agencies and private institutions may be tempted to sell currently unused or underused lands that now provide important groundwater recharge areas."

Kevin McDonald, senior policy advisor for The Nature Conservancy in New York, said groundwater protection areas were established on Long Island to help policy makers decide which areas to prioritize and protect. But there are no regulations that bar development in groundwater protection zones, he said.

“What we have found out is that areas not protected, not surprisingly, get developed,” McDonald said.

The value of properties within those areas is increasing over time as the number of open tracts of land continues to dwindle, especially in Nassau, McDonald said.

By expanding an already protected area, the North Shore Land Alliance is abiding by a core principle of land conservation, he said: Protect areas that are near already protected spaces.

"All efforts that can result in more places for the public to enjoy in perpetuity is a good thing that future generations will thank the present generation for," McDonald said.