(CNN) — Thanks to digital effects, filmmakers today can create almost anything -- monsters, aliens, tornadoes, tsunamis -- on movie screens.
But when it comes to spectacular natural scenery, it's hard to replicate the pristine beauty and wonder of real-life wilderness.
Ask the makers of "Star Trek V: The Final Frontier": A computer-generated rock face can't measure up to the grandeur of Yosemite's El Capitan.
Or George Lucas, who used Death Valley National Park, along with Tunisia, as scenery for the desert planet Tatooine in the first "Star Wars."
Or the makers of the original "Planet of the Apes," who thought the red-rock landcape of Glen Canyon National Recreation Area would make a neat monkey planet. So when Hollywood needs a gorgeous or otherworldly backdrop, it has long turned to federally protected wilderness.
Over the past 50 years America's natural wonders have filled in onscreen for the Old West, for wintry Siberia and even for planets in a certain galaxy far, far away.
Here's a look at some of their most notable movie cameos:
'E.T. the Extra-Terrestrial'
Steven Spielberg shot most of "E.T." on soundstages that doubled for Elliott's suburban home.
But for the forest scenes at the beginning and end of the movie -- when E.T. is stranded on Earth, and later when he reconnects with his spaceship to fly home (say it with me: "I'll be right heeere") -- Spielberg ventured to the dense redwood forests of Northern California, near Crescent City.
These redwoods also portrayed the forest moon Endor in "Return of the Jedi."
'Butch Cassidy and the Sundance Kid'
This classic outlaw movie was filmed all over the American West and Mexico (filling in for Bolivia).
The famous scene where Butch and Sundance leap off a cliff into a river to avoid their pursuers was shot in Colorado, but the movie's most spectacular backdrops were at Zion National Park, in southwestern Utah.
The scene where Paul Newman squires Katharine Ross around on a bicycle was filmed just outside the park in the ghost town of Grafton, whose faded buildings are now being restored to their frontier glory.
'National Lampoon's Vacation'
Remember that scene where the Griswolds stop at the Grand Canyon and Clark, having just stolen from the lodge's cash register, gazes at it for about two seconds before hustling his family back in the car?
Props to director Harold Ramis, who hauled a crew to Arizona just to film that brief scene at the classic El Tovar lodge and an overlook on the canyon's South Rim.
'Close Encounters of the Third Kind'
Many Americans weren't aware of this strange geological feature until Spielberg spotlighted it in the climax of his 1977 movie about friendly aliens who decide to touch down on Earth -- in northwestern Wyoming.
Devils Tower, a dramatic butte that rises 1,267 feet above the surrounding hills, is popular with climbers and is a sacred site to some Native Americans.
'Dances with Wolves'
Most of this Kevin Costner epic Western was shot on private ranchland in South Dakota, although the Badlands makes a brief early appearance on Lt. Dunbar's wagon train ride from Fort Hays to his lonely frontier outpost.
The park's trippy landscape also became an alien planet filled with giant warmongering insects in "Starship Troopers."
'Indiana Jones and the Last Crusade'
One of the highlights of the third movie in the Indiana Jones series was the prologue sequence, which explained how young Indy (River Phoenix) got his fedora, his chin scar and his fear of snakes.
The scene opens in Arches National Park, where Indy encounters a band of grave robbers in a cave before a madcap chase on a circus train.
The unique red-rock formations of Arches, in southeastern Utah, also hosted the cop-in-the-trunk scene in "Thelma and Louise."
'The River Wild'
Yep, that really was Meryl Streep doing some of her own rafting stunts in this 1994 adventure thriller, which was filmed on the rugged Flathead and Kootenai rivers in and around Glacier National Park in Montana.
Thrill-seekers can follow in her watery path by booking whitewater rafting trips on the Middle Fork of the Flathead, which forms the southwestern border of this spectacular national park.