Grand Teton National Park310,000 acres in northwestern Wyoming — the 13,775-foot Grand Teton rises 7,000 feet above Jackson Hole, with 200+ miles of trails and the 25-mile Teton Park Road

Grand Teton National Park was first established February 26, 1929 — but only protected the peaks themselves, leaving Jackson Hole vulnerable to subdivision. Beginning in 1927, John D. Rockefeller Jr. quietly bought 35,000 acres of valley ranchland through a front company (the Snake River Land Company), intending to donate it to the federal government as parkland. Local opposition was furious — Wyoming politicians blocked the gift for seventeen years. In 1943 President Roosevelt used the Antiquities Act to declare Jackson Hole National Monument; in 1950 Congress finally combined the original park, the monument, and the Rockefeller donation into the Grand Teton National Park we know today. The Teton Range itself is geologically young (the youngest of the Rocky Mountains, uplifted starting only about 9 million years ago) but the rocks at its core are nearly 2.7 billion years old — the oldest in any American national park.

The Teton Range runs forty miles north–south along the western edge of Jackson Hole, with no foothills to soften the rise. Twelve named peaks climb above 12,000 feet, with the namesake Grand at 13,775. The range catches enough snow to support a dozen named glaciers — small (Schoolroom Glacier on the Teton Crest Trail is the most-photographed) but persistent. Below the peaks: Jackson Lake (15 miles long, 438 feet deep, dammed in 1916), Jenny Lake (the most-visited day-hike trailhead in the park), String Lake (the kid-friendly paddleboard lake), Leigh Lake, and the Snake River — Snake River Overlook is where Ansel Adams took his famous 1942 black-and-white. Three valley landmarks frame any visit: the John Moulton barn on Mormon Row (the most-photographed barn in the U.S.), the Chapel of the Transfiguration in Moose (1925, with a window framing the Cathedral Group), and the four elk-antler arches at Jackson Town Square.

Plan four to seven days. Fly into Jackson Hole Airport (the only commercial airport inside a U.S. national park). Stay in Jackson (the lively gateway town), Moose (in-park lodging at Dornan's), Moran (Jackson Lake Lodge or Colter Bay), or Teton Village (the Jackson Hole Mountain Resort base). Drive the inner loop (Teton Park Road) for the close-up views and the outer loop (Highway 191) for the wildlife and the Snake River Overlook. Hike Cascade Canyon to Hidden Falls — an 8-mile round-trip, or 5 miles if you take the Jenny Lake boat shuttle ($20 round-trip). Take the Aerial Tram at Jackson Hole Mountain Resort to 10,450-foot Rendezvous Peak for the eagle-eye view. Wildlife is the other reason people come: bison and pronghorn on Antelope Flats, moose at Oxbow Bend at dawn, grizzlies and black bears throughout the park (carry bear spray). Reserve lodging six to nine months out for July and August.