The Cascade Route to Grand Coulee

The two destinations named on the cover anchor a classic mid-century Pacific Northwest road trip. The Cascade Highway (either US-2 over Stevens Pass or SR-20 through the North Cascades, both designated in different periods as the "Cascade Hwy") crosses the mountain wall separating western Washington from the dry interior plateau. Grand Coulee Dam, built 1933–1942 on the Columbia River in the eastern part of the state, was — and remains — one of the largest concrete structures ever built: 550 feet high and nearly a mile long. The reservoir it created, Lake Roosevelt, stretches 151 miles north to the Canadian border and drew boaters and campers from the postwar era onward, which explains the sailboat.

The illustration style — bold black outlines, flat fills of pink, yellow, sky blue, and ochre — places this squarely in the early-to-mid 1970s vocabulary of American government and tourism printing. Washington's state agencies promoted road travel aggressively in this period, often pairing scenic and recreational imagery with historical nods: here, the horse-drawn wagon gestures at the pioneer trails and wagon roads that preceded the paved routes, while the dome visible behind the wagon team appears to be the Washington State Capitol in Olympia — a standard emblem of state identity in promotional materials regardless of the map's actual coverage.

No publisher's name appears on the cover. Maps of this type were typically produced by Washington's Department of Commerce and Economic Development or, later, the Washington State Department of Transportation, often printed by commercial lithography shops under contract. Without the interior or back panel, attributing the specific edition is not possible.