The 417 U.S. National Park Service sites added $34.9 billion to the U.S. economy in 2016. The total was $2.9 billion more than in 2015, said Secretary of the Interior Ryan Zinke this week in San Francisco.

In 2016, national parks supported 318,000 jobs in hospitality, retail, transportation, and recreation industries in surrounding towns of these parks. That’s twice as many as all fossil fuel industry jobs in the U.S. Coal, oil, and gas industries combined employed around 150,000 Americans in 2016.

The 2016 National Park Visitor Spending Effects, an annual peer-reviewed economics study, reported that 331 million visitors to the National Parks in 2016, a 7.7 percent increase from 2015.

According to the 2016 report, 31.2 percent of the $34.9 billion dollar output came from lodging, followed by food and drink at 27.2 percent, with gas and oil, park admissions, souvenirs, local transportation, and camping fees accumulating the rest.

With more people visiting and spending at National Parks and surrounding communities each year, it is even more necessary for the parks to invest in infrastructure.

“With continued record visitation, it’s time to start thinking about accessibility and infrastructure. Last week, it was great to see the team at Yosemite opening up areas with new wheelchair accessible trails. In the coming years, we will look at ways to make innovative investments in our parks to enhance visitor experiences and improve our aging infrastructure,” said Zinke.