Tourism generated nearly $31 million for communities near the Vicksburg National Military Park in 2012, but effects of 2013’s federal government shutdown remain unknown.

The news was part of a peer-reviewed spending analysis by U.S. Geological Survey economists for the National Park Service. The study looked at economic impact of spending and visits within 60 miles of a national park. It also looked at effects of the 16-day shutdown of the federal government last October on the nation’s parks.

“Vicksburg National Military Park is proud to welcome visitors from across the country and around the world,” VNMP Superintendent Michael Madell said in a statement. “We are delighted to share the story of this place and the experiences it provides and to use the park as a way to introduce our visitors to this part of the country and all that it offers.

Precise numbers show visits at 573,252 and spending at $30.8 million. The spending supports 454 jobs in the local area, the study said.

National park tourism is a significant driver in the national economy, returning $10 for every $1 invested in the National Park Service, Madell said.

“We appreciate the partnership and support of our neighbors and are glad to be able to give back by helping to sustain local communities.”

The report showed direct spending nationwide by 283 million park visitors nationwide in 2012 hit $14.7 billion. Spending supported 243,000 nationally, with 201,000 found in the “gateway communities,” or areas of local visitors.

The study excluded parkways, such as Natchez Trace, and national memorials from its shutdown analysis due to access issues during the 16 days, it said. Effects of the shutdown on Vicksburg National Military Park was not included in the study, though Gettysburg NMP was. The latter lost $2.5 million in visitor spending due to the shutdown, the study said.

When reached Wednesday, Madell said the term “gateway” is one that “doesn’t translate well to Vicksburg” due to its size. In the vernacular of the study, Madell said, Vicksburg itself is the gateway community for the park.

The study notes that it’s not known how people who wanted to visit national parks changed their plans during and after the government closure.

All 401 national parks closed during the government shutdown. Visitation declined by more than 7.88 million people and $414 million in park-related visitor spending in gateway communities across the country compared to average foot traffic for the previous three Octobers. The biggest loss in raw traffic occurred in and around Great Smoky Mountains National Park, in Tennessee and North Carolina, while the biggest loss as a percentage of usual business was Manassas National Park, in Virginia, which lost 80 percent of its recent average of visitors.