Cascade on the Columbia River.1895 Road Map of OregonThe Columbia: America's Great Highway Through the Cascade MountaProposed Highways1916 Planned State Routes1918 Traffic Map (OHC)1920 Paving (OHC)1920 Tentative System Map (OHC)1920 System Map (OHC)1939 Highway Map1920 OHC Signage (OHC)Part of Mt. Hood Quadrangle, Showing Columbia River Highway, Mt.National Park Circuit Mather's Plan1918 Vista House Dedication - Tunnel Gallery - HCRH Van Tour1988 Vista House Dedication - Tunnel Gallery - HCRH Van TourWanapum Dam CrackPony Interpretive Sign - HCRH Van Tour