Photo: Mason Trinca, Special To The Chronicle Photo: Courtesy Michael Furniss Photo: Tom Stienstra, Tom Stienstra / The Chronicle Photo: NPS Photo: Christy Morgan Photo: California Department Of Parks And Recreation Photo: California Department Of Parks And Recreation Photo: Tom Stienstra, Tom Stienstra / The Chronicle Photo: California Department Of Parks And Recreation Photo: California Department Of Parks And Recreation Photo: Seascape Restaurant Trinidad Photo: PunkToad/Wikipedia Commons

Nearly 1,000 acres of redwood forest in the Santa Cruz Mountains will be protected from development thanks to an unusual deal brokered between a Bay Area land trust and a lumber company.

The Peninsula Open Space Trust and the McCrary family, who owns Big Creek Lumber, announced Tuesday an $11.7-million deal that amounts to a land swap of sorts.

Under the deal, Palo Alto-based POST will pay $3.5 million to Big Creek Lumber to purchase a 320-acre property of mature redwood groves at Gazos Creek, just south of Butano State Park in San Mateo County. The space will be open to the public and fall under the management of the Sempervirens Fund, a land trust in Los Altos.

The property is especially valuable to environmentalists as it falls within one of just seven critical habitat areas in the region for the endangered marbled murrelet, a small seabird.

POST will also purchase 617 acres of second-growth redwood forest from Cal Poly for about $8 million. The property is situated within the upper watershed of Aptos Creek in Corralitos.

ALSO READ: 'Poultry grim reaper' comes to NorCal

Here's where things become interesting: POST will transfer ownership of the Aptos land to Big Creek Lumber, a family-owned-and-operated company based in Davenport, near Santa Cruz. POST is making the transfer under a conservation easement that protects the parcel from development and puts restrictions on lumber harvesting.

"It's a win-win arrangement that benefits the forest and shows just how far conservationists and timber companies have come," said Walter T. Moore, president of POST, in a statement.

The Aptos parcel has been routinely logged over the years, but the easement places strict regulations on Big Lumber Creek, which will also extend to any company who might purchase the land in the future. Under the contract, Big Lumber Creek cannot clear cut or build new roads without POST's agreement. The company can log the area no more than once every decade. Only wood that grew since the last logging can be removed.

Sam Schuchat, executive officer of the California State Coastal Conservancy, said in a statement that the deal could provide a "model for similar protections and partnerships in the Santa Cruz Mountains and elsewhere."

ALSO: 5 best parks in California for wheelchairs

"It provides for optimal land uses: preserving endangered species habitat and working forest, along with watershed protections and permitting public access to the Gazos property."

In total, the deal preserves 937 acres of Santa Cruz Mountains redwoods.

"Together," Moore said, "we envision a future where the communities of people and wildlife that surround and depend upon these forests all benefit from the very positive environmental and economic outcomes that this collaboration will produce."

Read Michelle Robertson's latest stories and send her news tips at michelle.robertson@sfgate.com.

Start receiving breaking news emails on wildfires, civil emergencies, riots, national breaking news, Amber Alerts, weather emergencies, and other critical events with the SFGATE breaking news email. Click here to make sure you get the news.