The park service's sites around the country hosted a record-breaking 307.2 million visits, according to NPS data released Wednesday.
The Blue Ridge Parkway took the top spot in the National Park Service's list of the most visited places in the park system, which includes the 59 headliner national parks as well as historic sites, lakeshores, seashores and more.
Great Smoky Mountains National Park was the most popular of the 59 sites officially called national parks.
The National Park Service's 410 park sites encompass more than 84 million acres around the country.
"That kind of takes your breath away for a second," said National Park Service Director Jonathan B. Jarvis. "But we're also getting ready to welcome even more people -- the next generation of park visitors, supporters and advocates -- in this, the centennial year of the National Park Service."
Many parks are already posting historic visitation records.
Grand Canyon National Park surpassed 5 million annual recreation visits for the first time in 2015, while Yellowstone and Rocky Mountain National Parks each surpassed 4 million annual recreation visits for the first time. A total of 57 parks set a new record for annual recreation visits.
When Yellowstone National Park was the first national park created in 1872, barely anyone came to visit -- there wasn't yet a railroad to the park, and it was extremely hard to get to, due to its remote location.
Rangers didn't start keeping attendance records until 1904, and there were 120,000 visits to America's 11 national parks that year.
By the time President Woodrow Wilson signed the Organic Act creating the National Park Service on August 25, 1916, there were 14 national parks, 21 monuments and two reservations to visit. Rangers recorded 326,000 visits to those sites that year.
Now there are 410 sites, including the newest Castle Mountains National Monument in California, which was designated a national monument on February 10.
Last year's record-breaking 307 million visits represents a 5% increase -- 14.4 million more visits -- compared to 2014.
In 2013, the national park sites counted 273.6 million visits, the same year that the 16-day U.S. government shutdown forced many national sites to close.
Many more visitors are expected to explore the parks in the agency's centennial year, partially the result the #FindYourPark
campaign led by the National Park Service and the non-profit National Parks Foundation
The Blue Ridge Parkway had more than 15 million visits last year, while second-place Golden Gate National Recreation Area hosted 14.9 million visits. Great Smoky Mountains National Park came in third place in the list of most visited park sites with 10.7 million visits.
Top 10 most-visited National Park Service sites
1. Blue Ridge Parkway (15.0 Million)
2. Golden Gate National Recreation Area (14.9 million)
3. Great Smoky Mountains National Park (10.7 million)
4. Lincoln Memorial (7.9 million)
5. Lake Mead National Recreation Area (7.30 million)
6. Geo Washington Memorial Parkway (7.29 million)
7. Gateway National Recreation Area (6.4 million)
8. Natchez Trace Parkway (5.8 million)
9. Vietnam Veterans Memorial (5.6 million)
10. Grand Canyon National Park (5.5 million)
Top 10 most-visited national parks
1. Great Smoky Mountains National Park (10.7 million)
2. Grand Canyon National Park (5.5 million)
3. Rocky Mountain National Park (4.16 million)
4. Yosemite National Park (4.10 million)
5. Yellowstone National Park (4.1 million)
6. Zion National Park (3.6 million)
7. Olympic National Park (3.3 million)
8. Grand Teton National Park (3.1 million)
9. Acadia National Park (2.8 million)
10. Glacier National Park (2.4 million)