While I can’t drive to Hawaii, I have visited all the other sites in the western region, including all the sites below and these national historic and scenic trails: Arizona NST, California Pioneer NHT, Juan Bautista de Anza & Old Spanish NHTs, Pacific Crest NST, and the Pony Express & Butterfield Overland NHTs.

Arizona

• National Parks
  • Grand Canyon, Petrified Forest, and Saguaro
• National Monuments
  • Canyon de Chelly, Casa Grande Ruins, Chiricahua, Montezuma Castle, Navajo, Organ Pipe Cactus, Pipe Spring, Sunset Crater Volcano, Tonto, Tuzigoot, Walnut Canyon, and Wupatki
• National Historic Sites, Historical Parks and Memorials
  • Coronado N Mem, Fort Bowie NHS, Hubbell Trading Post NHS, and Tumacácori NHP
• National Heritage Areas: Santa Cruz Valley and Yuma Crossing

California

• National Parks
  • Channel Islands ℬ, Death Valley ℬ, Joshua Tree ℬ, Kings Canyon ℬ, Lassen Volcanic, Pinnacles, Redwood, Sequoia ℬ, and Yosemite
• National Monuments
  • Cabrillo, Castle Mountains, César E. Chávez, Devil’s Postpile, Lava Beds, Muir Woods, and Tule Lake
• National Historic Sites, Historical Parks and Memorials
  • Eugene O’Neill NHS, Fort Point NHS, John Muir NHS, Manzanar NHS, Port Chicago Memorial, Rosie the Riveter WWII Home Front NHP, and San Francisco Maritime NHP
• National Preserves, Recreation Areas, and Seashores
  • Golden Gate NRA ℬ, Mojave Preserve ℬ, Point Reyes Seashore, Santa Monica Mountains NRA, and Whiskeytown NRA
• National Heritage Areas: Sacramento-San Joaquin Delta

Nevada

• Great Basin National Park, Lake Mead NRA and Tule Springs Fossil Beds National Monument.