The Whidbey Camano Land Trust has another 90 days to raise money for the preservation of the former Trillium Woods property northwest of Freeland, trust officials said late Thursday.

Three Snohomish County banks extended the original June 10 deadline for raising the $4.2 million needed to buy the 664-acre property, the largest single-owner forest remaining on Whidbey Island.

The trust now must find an additional $1.8 million by Sept. 10 to reach its goal to preserve the property for rural recreation, said Pat Powell, executive director of the land trust.

In the past 12 weeks, individuals have donated in amounts ranging from pocket change to $100,000 checks. As of Thursday, the nonprofit land trust had commitments for $2.4 million, Powell said.

Donations so far are split about evenly between cash and pledges, trust officials said.

If the trust fails to reach its goal, donations for Trillium Woods will be applied to other land-trust projects, unless the donor has specified otherwise, trust officials said.

“We’re exhausted and elated,” she said Thursday. “Exhausted because we’ve been working so hard toward this deadline and elated because the banks have given us more time.”

Jeff Lewis, president and chief operating officer of Shoreline Bank, principal owner of the property, said Thursday that the new deadline would be the trust’s only extension.

“The land trust’s ability to raise this much money is remarkable,” Lewis said. “But we’re under a regulatory obligation to sell non-earning assets and can’t extend this deadline any further.

“We have more than $4 million tied up in something that’s earning nothing, and is costing us every day,” he said.

Shoreline Bank, Coastal Community Bank and North County Bank acquired the property at public auction this past fall when its Arlington developer defaulted on $5 million in loans.

More than 80 community groups have endorsed the land trust’s efforts to take over the property, which would be administered by Island County and maintained by volunteers.

The original 750-acre property is west of Highway 525 about a mile north of Mutiny Bay Road. The woodland, adjacent to South Whidbey State Park, is laced with more than 10 miles of trails, and has been a popular hiking and horseback-riding area.

Known most recently as Estates at Whidbey, the property fell into foreclosure after owner Jesse Molnick, who subdivided the property to contain more than 120 houses, ran into financial trouble with the project barely under way.

The Freeland Water and Sewer District recently bought 80 acres to use for its proposed sewer system.

The property has had a blustery history in the past 30 years.

In 1988, it was the site of controversy when Trillium Corporation of Bellingham, owners at the time, clearcut the area.

Protesters gathered at the property and blocked an entrance in a failed attempt to stop the logging.

The land trust is a local nonprofit organization working to protect natural habitats, scenic vistas and working farms and forests in partnership with landowners and the community.

It permanently protects land on the two islands from development by buying property and conservation easements, and has secured more than 6,100 acres to date.

“All the people who haven’t contributed because they thought it couldn’t happen can go ahead and get their checkbooks out now,” Powell said.