RIVERSIDE — While Merck is closing its longtime manufacturing operation in Northumberland County, the pharmaceutical company is preparing a major expansion elsewhere in Pennsylvania.

The Riverside closure has already eliminated many jobs, with remaining shutdown work continuing.  Meantime. the state says Merck will invest $2.9 billion to expand its Montgomery County operations through 2030. Pennsylvania is providing $5 million to support the growth.

The investment includes a new $550 million research and development facility at Merck’s West Point campus, using robotics and artificial intelligence to help develop medicines.