Gift of Land by Nicholson Is Reported : Parks: Sixty acres in the Santa Monicas will join mountain preserve. The parcel is east of the San Diego Freeway.

The Santa Monica Mountains Conservancy has received a gift of 60 acres of parkland in the hills above Studio City from film star Jack Nicholson, sources familiar with the transaction said Wednesday.

Although conservancy officials would not name the donor, they described the land as “the most significant stretch of undeveloped ridgeline” between Mulholland Drive and Ventura Boulevard east of the San Diego Freeway.

“All I can say is it was an anonymous donation by a generous benefactor,” said Joseph T. Edmiston, the conservancy’s executive director.

But Turnley Walker, chairman of the Longridge-Alomar Neighborhood Committee, which is active in preservation efforts in the area, said the donor is Nicholson, as did a second source familiar with the deal.

Nicholson’s business manager declined comment when asked the source of the gift.

Officials said the parcel, which includes frontage on the north side of Mulholland and the west side of Coldwater Canyon Avenue, features an extensive native oak woodland and is habitat for deer.

It borders other tracts the conservancy has purchased or is trying to acquire in a continuing effort to preserve a continuous swath of wild-land habitat linking Griffith Park on the east to Topanga State Park on the west.

John A. Diaz, land acquisition chief for the conservancy, said a four-lot subdivision had been approved for the property, but that it “will now be available for all of the public to enjoy for all time.”

Word of Nicholson’s involvement will only enhance the conservancy’s budding reputation as park agency to the stars. A state parks agency that acquires land in the Santa Monicas and neighboring ranges, including the Simi Hills and Santa Susana Mountains, the conservancy announced in November that entertainer Barbra Streisand was giving it her Malibu estate for use as an environmental research center.

Previously, actors Warren Beatty and Peter Strauss and singer-songwriter Don Henley aided conservancy acquisitions. The agency last month got a film and television star on its board when Los Angeles Mayor Richard Riordan named Ed Begley Jr. to represent the city on the eight-member panel.