North of Colter Bay, the highway cruises along the shore of Jackson Lake for the next nine miles, providing some fine vantage points of the Tetons. The burned area on the opposite shore was ignited by lightning in the 1974 Waterfalls Canyon Fire, which consumed 3,700 acres. By late fall each year, Idaho spud farmers have drawn down water in the lake, leaving a long, barren shoreline at the upper end.

Shortly after the road leaves the upper end of Jackson Lake, a signboard announces your entrance into John D. Rockefeller Jr. Memorial Parkway. This 24,000-acre parcel of land was transferred to the National Park Service in 1972 in commemoration of Rockefeller’s unstinting work in establishing Grand Teton National Park. The land forms a connection between Grand Teton and Yellowstone and is managed by Grand Teton National Park.

Much of this area was severely burned by the 1988 Huck Fire, which began when strong winds blew a tree into power lines. Despite immediate efforts to control the blaze, it consumed 4,000 acres in the first two hours and later grew to cover nearly 200,000 acres, primarily within the Forest Service’s Teton Wilderness. Dense young lodgepole pines now carpet much of the land.

Flagg Ranch

On the northern end of Rockefeller Parkway is Flagg Ranch Resort (307/543-2861 or 800/443-2311, www.flaggranch.com), where facilities include a gas station, convenience store, gift shop, cabins, restaurant (daily 7 a.m.-10 p.m., $14-34), and campground with RV hookups. The Park Service operates little Flagg Ranch Information Station (307/543-2372, daily 9 a.m.-3:30 p.m. early June-early Sept.). During the winter, Flagg Ranch is the jumping-off point for snowcoach and guided snowmobile trips into Yellowstone; the road isn’t plowed north of this point.

Two nearby trails provide easy day hikes. The nearly level Polecat Creek Loop Trail is 2.3 miles round-trip and follows a ridge overlooking a marsh and through conifer forests. Flagg Canyon Trail is five miles round-trip and provides views of a rocky canyon cut through by the Snake River.

Grassy Lake Road

Grassy Lake Road takes off just north of Flagg Ranch Resort and continues 52 miles to Ashton, Idaho. It’s a scenic drive, but don’t attempt this narrow and rough dirt road with a trailer or an RV. This route provides a shortcut to the Bechler River area of Yellowstone and is a popular wintertime snowmobile route.

Huckleberry Hot Springs, a short hike north from the Grassy Lake Road]bridge over the Snake River, was the site of a public swimming pool until 1983, when it was razed by the Park Service. The hot springs are accessible via an unmaintained trail, but you’ll need to wade Polecat Creek to reach them. Although they remain very popular with hikers and cross-country skiers, it’s worth noting that the springs might pose a risk from high radiation levels and potentially deadly amoebae.

A few miles east of the Idaho-Wyoming border on Grassy Lake Road is Squirrel Meadows Guard Station (208/652-7442, www.fs.fed.us/r4/caribou-targhee), a two-room Forest Service cabin with bunk beds, a hand pump for water, and an outhouse. The cabin sleeps up to six for $35 (reservations at 518/885-3639 or 877/444-6777, www.recreation.gov, $9 fee). Wintertime access is via snowmobile or skis for the last 12 miles to the cabin from the Idaho side. Lodging is available just across the Idaho border at Squirrel Creek Guest Ranch (208/652-3972, www.idahoranch.com, $75-105 d).