A human National Park Service logo, formed on Tuesday, Aug. 25, 2016.
(Courtesy of the National Park Service)
Courtesy of the National Park Service
Gates of the Arctic National Park and Preserve in Alaska.
(Courtesy flickr/Zak Richter, National Park Service)
Courtesy flickr/Zak Richter, National Park Service
Hidden Lake at Glacier National Park in Montana.
(Courtesy flickr/Tim Rains, National Park Service)
Courtesy flickr/Tim Rains, National Park Service
Dall’s sheep on steep hillside in Arctic National Park and Preserve in Alaska.
(Courtesy flickr/Zak Richter, National Park Service)
Courtesy flickr/Zak Richter, National Park Service
Northern Lights dance across the sky in Denali National Park in Alaska.
(Courtesy flickr/Katie Thoresen, National Park Service)
Courtesy flickr/Katie Thoresen, National Park Service
Rocky Mountain National Park in Colorado.
(Courtesy flickr/M. Reed, National Park Service)
Courtesy flickr/M. Reed, National Park Service
The Big Bend at Zion National Park in Utah.
(Courtesy flickr, Cadence C. Cook, National Park Service)
Courtesy flickr, Cadence C. Cook, National Park Service
A shot of the Grand Canyon National Park in Arizona.
(Courtesy flickr/ M. Quinn, National Park Service)
Courtesy flickr/ M. Quinn, National Park Service
A full moon rises over the mountains in Denali National Park in Alaska.
(Courtesy flickr/Katie Thoresen, National Park Service)
Courtesy flickr/Katie Thoresen, National Park Service
The Big Bend at Zion National Park in Utah.
(Courtesy flickr, Cadence C. Cook, National Park Service)
Courtesy flickr, Cadence C. Cook, National Park Service
Autumn hits Oak Creek at Zion National Park in Utah.
(Courtesy flickr, Cadence C. Cook, National Park Service)
Courtesy flickr, Cadence C. Cook, National Park Service
Glowing Aspen in Glacier National Park in Montana.
(Courtesy flickr/National Park Service)
Courtesy flickr/National Park Service
Mount Rainier and Nisqually Glacier at dusk in Mount Rainier National Park in Washington.
(Courtesy flickr/National Park Service)
Courtesy flickr/National Park Service
Visitors viewing the inversion from Hopi Point along Hermit Road on the South Rim of Grand Canyon National Park in Arizona.
(Courtesy flickr/M. Quinn, National Park Service)
Courtesy flickr/M. Quinn, National Park Service
A photo taken on a clear, cold and windy New Year’s Day 2016 on the Grand Canyon. This view is from the Hermit Road Shuttle Bus Transfer Station, just west of Grand Canyon Village.
(Courtesy flickr/M. Quinn, National Park Service)
Courtesy flickr/M. Quinn, National Park Service
The treeless slopes of the Arctic Divide near the Nunamuit village of Anaktuvuk Pass. Gates of the Arctic National Park and Preserve in Alaska.
(Courtesy flickr/Sean Tevebaugh, National Park Service)
Courtesy flickr/Sean Tevebaugh, National Park Service
Waterfalls along the aqueduct in an Alaskan National Park.
(Courtesy flickr/Jacob W. Frank, National Park Service)
Courtesy flickr/Jacob W. Frank, National Park Service
Kolob Canyons at Zion National Park in Utah.
(Courtesy flickr/Cadence C. Cook, National Park Service)
Courtesy flickr/Cadence C. Cook, National Park Service
Dall’s sheep foraging on lichen in Arctic National Park in Alaska.
(Courtesy flickr/Zak Richter, National Park Service)
Courtesy flickr/Zak Richter, National Park Service
Mountain range sunset view in Glacier National Park
(Courtesy flickr/Tim Rains, National Park Service)
Courtesy flickr/Tim Rains, National Park Service
Preston Park, part of Glacier National Park in Montana.
(Courtesy flickr/Tim Rains, National Park Service)
Courtesy flickr/Tim Rains, National Park Service
Snoozing sea otter in Kenai Fjords National Park in Alaska.
(Courtesy flickr/National Park Service)
Courtesy flickr/National Park Service
Siyeh Pass Trail in Glacier National Park in Montana.
(Courtesy flickr/Tim Rains, National Park Service)
Courtesy flickr/Tim Rains, National Park Service
Lake McDonald of Glacier National Park in Montana.
(Courtesy flickr/Jacob W. Frank, National Park Service)
Courtesy flickr/Jacob W. Frank, National Park Service
A photo of Glacier National Park in Montana.
(Courtesy flickr/Jacob W. Frank, National Park Service)
Courtesy flickr/Jacob W. Frank, National Park Service
St. Mary Falls in Glacier National Park in Montana.
(Courtesy flickr/Tim Rains, National Park Service)
Courtesy flickr/Tim Rains, National Park Service
Saint Mary Lake Sunset at Glacier National Park in Montana.
(Courtesy flickr/Jacob W. Frank, National Park Service)
Courtesy flickr/Jacob W. Frank, National Park Service
Glaciers at the Denali National Park and Preserve in Alaska.
(Courtesy flickr/National Park Service)
Courtesy flickr/National Park Service
Wildflowers (Stenotus acaulis, cushion goldenweed) on Blacktail Deer Plateau in Yellowstone National Park.
(Courtesy flickr/Neal Herbert, National Park Service)
Courtesy flickr/Neal Herbert, National Park Service
Kenai Fjords National Park in Alaska.
(Courtesy flickr/National Park Service)
Courtesy flickr/National Park Service
Dall’s sheep at an Alaska National Park
(Courtesy flickr/National Park Service)
Courtesy flickr/National Park Service
BRYCE CANYON NATIONAL PARK, UT – AUGUST 12: Visitors walk on switchbacks on the Navajo Loop Trail through fin rock formations on August 12, 2016 in Bryce Canyon National Park, Utah.
(Photo by Ethan Miller/Getty Images)
Photo by Ethan Miller/Getty Images
BRYCE CANYON NATIONAL PARK, UT – AUGUST 12: Bristlecone Point is illuminated by the setting sun above hoodoos viewed from Sunset Point overlooking Bryce Amphitheater on August 12, 2016 in Bryce Canyon National Park, Utah.
(Photo by Ethan Miller/Getty Images)
Photo by Ethan Miller/Getty Images
YOSEMITE NTL PARK, CA – JUNE 18: El Capitan above the Merced River on June 18, 2016 in Yosemite National Park, California. President Barack Obama spoke to a crowd at Yosemite marking the centennial of the National Park Service which began on August 25, 1916.
(Photo by David Calvert/Getty Images)
Photo by David Calvert/Getty Images
CHICAGO, IL – JUNE 11: The Treme Brass Band performs at the National Park Service Centennial Event at Washington Park on June 11, 2016 in Chicago, Illinois.
(Photo by Timothy Hiatt/Getty Images for the National Park Foundation)
Photo by Timothy Hiatt/Getty Images for the National Park Foundation
CHICAGO, IL – JUNE 11: General atmosphere of the National Park Service Centennial Event at Washington Park on June 11, 2016 in Chicago, Illinois.
(Photo by Timothy Hiatt/Getty Images for the National Park Foundation)
Photo by Timothy Hiatt/Getty Images for the National Park Foundation
CHICAGO, IL – JUNE 11: Chicago’s Hypnotic Brass Ensemble performs at the National Park Service Centennial Event at Washington Park on June 11, 2016 in Chicago, Illinois.
(Photo by Timothy Hiatt/Getty Images for the National Park Foundation)
Photo by Timothy Hiatt/Getty Images for the National Park Foundation
YOSEMITE NTL PARK, CA – JUNE 18: Half dome at seen from the east on June 18, 2016 in Yosemite National Park, California. President Barack Obama spoke to a crowd at Yosemite marking the centennial of the National Park Service which began on August 25, 1916.
(Photo by David Calvert/Getty Images)
Photo by David Calvert/Getty Images
YOSEMITE NTL PARK, CA – JUNE 18: President Barack Obama speaks in front of Cook’s Meadow and Yosemite Falls on June 18, 2016 in Yosemite National Park, California. Obama is marking the centennial of the National Park Service which began on August 25, 1916.
(Photo by David Calvert/Getty Images)
Photo by David Calvert/Getty Images
CHICAGO, IL – JUNE 11: Common and members of the National Park Service attend the National Park Service Centennial Event at Washington Park on June 11, 2016 in Chicago, Illinois.
(Photo by Timothy Hiatt/Getty Images for the National Park Foundation)
Photo by Timothy Hiatt/Getty Images for the National Park Foundation
NEW YORK, NY – AUGUST 22: A view of New York City skyline during the National Park Foundation’s #FindYourPark event, celebrating the National Park Service’s centennial at Brooklyn Bridge Park on August 22, 2016 in New York City.
(Photo by Neilson Barnard/Getty Images for National Park Service)
Photo by Neilson Barnard/Getty Images for National Park Service
CHICAGO, IL – JUNE 11: General atmosphere of the National Park Service Centennial Event at Washington Park on June 11, 2016 in Chicago, Illinois.
(Photo by Timothy Hiatt/Getty Images for the National Park Foundation)
Photo by Timothy Hiatt/Getty Images for the National Park Foundation