"Once again, Toyota is proving to be one of West Virginia's biggest boosters and economic success stories, and I never miss a chance to brag on the fantastic teamworkers who make up its Buffalo plant," Rockefeller said in a statement.
"When I first visited with Toyota officials more than 30 years ago, I promised their investment in West Virginia would be met with the hardest and most dedicated workforce," he said. "Today's announcement validates that promise, and I thank Toyota for their ongoing support of our state."
The latest expansion will bring the company's total overall investment in West Virginia to more than $1.4 billion.
More than 1,300 people work at the plant today. Factoring in secondary jobs at other companies with business tied to the plant's production, Toyota officials have estimated the Buffalo plant is responsible for about 10,000 jobs across the region.
The plant produces powertrain units for nine Toyota and Lexus models assembled at other plants across North America.
Powertrain units are the vehicle components that produce energy and make a vehicle go. They include engines and automatic transmissions, which are produced at the Buffalo plant.
The expansion will boost the plant's overall production capacity from 500,000 to 740,000 transmissions each year.
In May, state and company officials celebrated the 10 millionth powertrain engine unit to come off the production lines at the plant. The Buffalo plant is the only Toyota plant outside of Japan to celebrate such a milestone.
Every 20 seconds, a Toyota vehicle rolls off a North American assembly line containing a powertrain product produced in West Virginia.
One of every four Toyota vehicles on the road today contains a Buffalo-manufactured product. The combined output of all engines produced at the plant since 1998 tops 1 billion horsepower.
Officials said in May if every part produced at the plant since production began in 1998 were lined up, the line would stretch for more than 3,000 miles.
In addition to jobs, the company has contributed nearly $6.5 million to organizations throughout the community and state, including $32,500 in donations made Wednesday to 13 schools in Putnam, Mason, Cabell and Kanawha counties.