Wyoming saw $723.3 million in spending by visitors to parks and monuments run by the National Park Service; Montana, $397.3 million; and Idaho, $29.4 million.
On Friday, the National Park Service released a report that says spending on hotels, restaurants, gas and supplies by visitors to U.S. national parks in 2013 contributed $14.6 billion in economic benefits to communities within 60 miles of the parks nationwide.
Wyoming, Idaho and Montana share parts of Yellowstone National Park, where visitors spent almost $382 million in nearby communities. Yellowstone had 3.18 million visitors in 2013.
The study showed that 49 percent of Yellowstone spending benefited Wyoming and 51 percent benefited Montana.
Visitors to Grand Teton National Park and the adjoining John D. Rockefeller Jr. Memorial Parkway spent more than $502 million in northwest Wyoming and eastern Idaho communities.
"We understand the part we play in creating a healthy and sustainable economic base, and we appreciate the support of area businesses, neighbors and park partners for our national parks," Grand Teton National Park Superintendent David Vela said in a statement.
More than 2 million visited Glacier National Park in Montana, spending more than $178 million.
Communities around Craters of the Moon National Monument in southern Idaho saw $6.6 million in economic benefits from visitors.
"This new report confirms that national park tourism is a significant driver in the national economy, returning $10 for every $1 invested in the National Park Service," Sue Masica, the National Park Service's Intermountain Region director, said in a news release.
The park service study said the biggest part of visitor spending nationally was for lodging, at 30.3 percent. Food and beverage purchases accounted for 27.3 percent of spending, while gas and oil accounted for 12.1 percent. Park admission and fees accounted for 10.3 percent of spending nationally, and souvenirs and other expenses were pegged at 10 percent.
The park service concluded that around the country, restaurant and bar spending that depends on national parks created 50,000 jobs, while lodging depended on national parks for 38,000 jobs.
The study put total park visitors around the United States in 2013 at 273.6 million, down from 282.7 million in 2012. Total park-dependent visitor spending was put at $14.6 billion, slightly down from the year before. The survey said that around the country the national parks supported 237,599 jobs.