North Cascades National Park

The turquoise reservoir most people picture when they think of this corridor. The color is glacial rock-flour, fine rock ground by upstream glaciers and held in suspension, which scatters green-blue light when the sun is on the water. Per NPS it reads best mid-morning to mid-afternoon. The lake is not a natural feature: it sits behind Seattle City Light's Diablo Dam, completed in 1930, in a drainage the Upper Skagit used as a travel and fishing corridor. The signed Diablo Lake Overlook on State Route 20 is the stop most drivers pull over for.

A 9,131-foot glacier-clad peak in the park's northwest corner. One catch for families driving the corridor: the reflection view that shows up on calendars and book covers is from Picture Lake in the adjacent Mount Baker-Snoqualmie National Forest, reached by State Route 542, not by State Route 20. From the main highway you see the range's other faces.

An open alpine meadow at a saddle that the Lake Chelan and Upper Skagit peoples have used as a trans-mountain trade and travel route since time immemorial. Per the NPS Native Peoples page they named the head of Lake Chelan Stehekin, the way through. Reaching it is a strenuous full day: the trailhead is at the end of Cascade River Road (gravel, frequently washed out, generally open mid-June through October), and the trail climbs about 3.7 miles of switchbacks to the pass, with Sahale Arm continuing above. Older kids and steady walkers only.

The complex holds more than 300 glaciers per NPS, more than any U.S. park outside Alaska, roughly a third of all the glaciers in the lower 48. None sit at the end of a casual family walk. The point is the science and the record. The North Cascade Glacier Climate Project keeps one of the longest continuous glacier-mass-balance records in the contiguous U.S. The hook for kids: the same rock-flour these glaciers grind off the mountains is what turns Diablo Lake green downstream.

A 23-mile-long reservoir behind Ross Dam (Seattle City Light, built to its full 540-foot height by 1949), running north to the Canadian border at Hozomeen. The upper Skagit valley now under the water was Upper Skagit and Nlaka'pamux travel and harvest country before the dams. No road reaches the main body of the lake: access is by the Ross Lake Resort water taxi, by boat, or on foot, with the Ross Dam Trail from State Route 20 the standard short approach. One of the five stops on the classic corridor day, and the quietest.

Newhalem is the only developed cluster on the corridor, a Seattle City Light company town that pre-dates the park and sits in Upper Skagit homeland along the Skagit travel route. It holds the North Cascades Visitor Center (technically in Ross Lake NRA, not the park unit), the 100-foot accessible Sterling Munro Boardwalk to a wall of peaks, and Ladder Creek Falls, lit at night behind the Gorge powerhouse and reached by a short trail and footbridge. Free. The pictured cascade is the nearby Gorge Creek Falls, the documented roadside falls on this stretch of State Route 20.

A National Register historic homestead in the roadless Stehekin valley that still grows heirloom apples, with an autumn cider pressing families can walk through. Per NPS it is a working farm, not a static museum. Stehekin sits at the head of Lake Chelan, the corridor the Chelan and Lake Chelan peoples named Stehekin, the way through. Reached only by the Lady of the Lake ferry from Chelan, by floatplane, or on foot, then the valley shuttle.

The signed pullout on State Route 20 looking down on the turquoise reservoir, with Colonial, Pyramid, and Davis peaks behind it. Paved, railed, steps from the car, per NPS. The color reads best mid-morning to mid-afternoon, when the sun is on the lake. Come too early or too late and the green goes flat. The first stop most families remember from the drive.

The east-side bookend to the Diablo Lake Overlook: a short paved loop from a parking lot to a railed viewpoint over the granite Liberty Bell group and the Early Winters Spires, with the State Route 20 hairpin dropping away below. Per the USFS Okanogan-Wenatchee forest it sits at the east end of the corridor and closes with the highway in winter, typically mid-November through mid-May.

A short walk-up to a waterfall whose uppermost tier drops about 312 feet in the Stehekin valley, reached by the NPS shuttle from the ferry landing per NPS. The easy payoff for families who make the boat trip up Lake Chelan into the roadless valley: the falls drop off a cliff a short stroll from the shuttle stop. Confirm the exact distance and the shuttle schedule against the live NPS Stehekin page when you plan.

The corridor itself is gas-food-lodging-free, so the food a family needs sits in the gateway towns. Winthrop, at the east end of State Route 20 in the Methow Valley, keeps a preserved Old-West-styled boardwalk along Riverside Avenue, with a brewery and an ice-cream and candy shop among the stops, per the USFS Okanogan-Wenatchee listing of the gateway town. The practical fuel-and-supper stop coming off the east end of the highway. Marblemount plays the same role on the west.