AARoads:United States/Washington/Auto trails

• California-Banff "B" Line, Oregon (Walla Walla) to Idaho (Newport) via PSH 3, PSH 6
• Evergreen National Highway, Canada (Blaine) to Idaho (Clarkston) via PSH 1, PSH 8, PSH 3
• George Washington National Highway, Seattle to Idaho (Coeur d'Alene) via PSH 2
• Glacier Trail, Canada (Blaine) to Idaho (Newport) via PSH 1, PSH 2, PSH 6
• National Park to Park Highway, Oregon (Vancouver) to Idaho (Newport) via PSH 1 (branch on PSH 5, Tacoma-Rainier), PSH 2, PSH 6
• National Parks Highway (Northwest Trail), Oregon (Vancouver) to Idaho (Coeur d'Alene or Rathdrum) via PSH 1 (branch on PSH 5, Tacoma-Rainier), PSH 2
• Okanogan-Cariboo Trail, Wenatchee to Canada (Oroville) via PSH 10
• Pacific Highway, Oregon (Vancouver) to Canada (Blaine) via PSH 1
• Theodore Roosevelt International Highway, Oregon (Walla Walla) to Idaho (Newport) via PSH 3 (Eastern Division), PSH 6
• Yellowstone Trail, Seattle to Idaho (Coeur d'Alene) via PSH 2, PSH 3, PSH 2

By PSH

• PSH 1
  • 1910: Pacific Highway Association formed
  • 1913: Pacific Highway name assigned
• PSH 2
  • 1912: Yellowstone Trail Association formed
  • 1913: Sunset Highway name assigned
  • 1915: National Parks Highway Association formed
• PSH 3
  • 1913: Inland Empire Highway name assigned
• PSH 5
  • 1913: National Park Highway name assigned
  • 1916: National Park-to-Park Highway Association formed
  • by 1921: National Parks Highway Association extended route from Seattle to Mount Rainier
• PSH 8
  • 1917: Evergreen Highway Association formed
  • 1937: Evergreen Highway name assigned