If, like us, you obsess over Ansel Adams's photos of our national parks, you're going to love this. We dug up the backstories of three famous images, then called Don Olson, an Adams expert and astrophysicist at Texas State University, who used topographic maps and astronomical charts to help us identify the GPS coordinates of the locations where Adams composed his photos. —KYLE DICKMAN AND TIM SOHN
Tetons and the Snake River, Grand Teton National Park, 1942
The Spot: Snake River Overlook
Lat/Long: 43°45.250'N, 110°37.410'W
Adams visited the Snake River Overlook, just north of the town of Moose, and took five photos at the northeast end of the parking lot during a June thunderstorm. Trees now obscure the S-curve of river in the foreground.
Clearing Winter Storm, Yosemite National Park, circa 1935
The Spot: Tunnel View
Lat/Long: 37°42.948'N, 119°40.6122'W
This shot looks up the Yosemite Valley from a viewpoint near a wall in the parking lot at the east end of the Wawona tunnel—a popular spot on Highway 41. One winter afternoon, Adams caught the valley just as a storm ended. "I have been at this location countless times over many years," Adams wrote of the photo, "but only once did I encounter just such a combination of visual elements."
Mount McKinley and Wonder Lake, Denali National Park, 1947
The Spot: Wonder Lake
Lat/Long: 63°28.563'N, 150°51.639'W
Adams took this sunrise image—looking south across Wonder Lake to Mount McKinley—in July from a hill* situated between the lake's eastern shore and nearby Reflection Pond. Shooting under Alaska's midnight sun demanded a rough schedule: Adams left his camp after the 11:30 P.M. sunset and arrived at about 1:30 A.M., in time to snap a few shots before clouds rolled in.
*To confirm this location, park ranger Jon Paynter followed Olson's GPS coordinates and took 20 photos. Verdict: That's the spot.