SEATTLE–Twin Creeks Timber LLC , a joint venture originally formed in 2015 in part by Silver Creek Capital Management, a $6.3 billion alternative investment manager, to enable institutions to directly invest in high quality timber assets alongside a timberland operator, today announced that it will add 121,000 acres of timberland to its portfolio. Twin Creeks will purchase 100,000 acres located in the Southern U.S. from Weyerhaeuser Company and receive a contribution of 21,000 acres located in the Pacific Northwest from Green Diamond Resource Company. Through the addition of these timber assets, Twin Creeks will increase its Southern portfolio to 360,000 acres and add the Pacific Northwest to its portfolio. The timberland transactions are expected to close by year end.