Twin Creeks Timber LLC, a joint venture originally formed in 2015 in part by Silver Creek Capital Management and a $6.3 billion alternative investment manager, today announced that it will add 121,000 acres of timberland to its portfolio.

The firm will purchase 100,000 acres located in the southern U.S. from Weyerhaeuser Co. and receive a contribution of 21,000 acres located in the Pacific Northwest from Green Diamond Resource Co.

Twin Creeks also announced that it has repurchased Weyerhaeuser’s equity interest in the joint venture and will replace Weyerhaeuser as the joint venture’s timberland manager with Green Diamond Management Co.

“As a family-owned business with roots dating to 1890, Green Diamond is committed to long-term, high quality stewardship of timberland properties,” says Douglas Reed, president of that firm. “We are delighted to invest in and manage for Twin Creeks as their approach is aligned with our own.”

Green Diamond Resource Co. is a privately held forest products company that owns and manages working forest lands in Washington, Oregon and California.