You could see the domed roofs on the African-style huts an exit or two away, driving north up Highway 101.

“Silicon Valley” was a name people were already throwing around in the early 1980s, but there was little visible sign of it yet. No spiking home prices, no buses driving workers in from San Francisco and no office park buildings rising next to the freeways.

Returning to my hometown of Burlingame from a doctor’s visit at Kaiser in Redwood City, or an errand in Palo Alto, I’d press my nose against the glass as we passed Marine World Parkway, dreaming about the amazing other world they built on reclaimed tidelands.

Marine World/Africa U.S.A., an animal-themed amusement park planted on 66 acres now claimed by Oracle Corp. headquarters, seems like more of a mirage with each passing year. It opened in 1968 and moved to Vallejo in 1985, followed by a slow transformation into the current thrill ride-heavy Six Flags Discovery Kingdom.

But that passing time also highlights what a miracle the place was. Your old Marine World stories sound like tall tales, some of which still can’t be confirmed with a Google search.

The park was planned for Mill Valley in the 1960s, along Richardson Bay. The resort company behind the project got as far as architectural drawings; the planned Marine World was close enough to Highway 101 to see a killer whale jumping from your automobile. Marin County residents protested the news, and in true North Bay fashion — this was the populace that opted out of a BART extension — the Mill Valley City Council decided “that the project would be incompatible with the community’s residential character,” according to a 1962 Chronicle article.

The park opened in Redwood Shores in 1968, and from the beginning was locked in a financial struggle. But that thrifty seat-of-the-pants mentality is what fed into the park’s unforgettable character. Combine money troubles with wild animals (including some of the most efficient predators on the planet) and a culture that was less lawsuit-driven, and the result was a park that is mind-boggling to imagine in 2018.

The first star of Marine World was Judy the water-skiing elephant, a pachyderm that trainers placed on pontoon-like skis and dragged into the park’s lagoon. In the early 1970s, rock concerts were hosted at the park; Big Brother & the Holding Company, Elvin Bishop and Tower of Power all gigged at Marine World. Perhaps the most memorably random addition was Tiger Mountain Rapids, four water slides built into a painted fake mountain that was visible from the San Carlos and Belmont hills.

In the 1970s, the company that ran the failing park pulled out, and an ownership group run by general manager Mike Demetrios took over. Demetrios had a P.T. Barnum flair that landed him frequently in Chronicle columns, often pushing an earnest message of ecology and environmentalism. Whale shows at aquatic parks are seen as immoral acts now in the post-“Blackfish” documentary era, but in the 1970s and ’80s, environmental groups would host fundraisers at Marine World.

“Twenty years ago that cheetah or leopard would draw expressions like, ‘Wow, what a fur coat!’” Chronicle sports editor Art Rosenbaum wrote in a 1974 column about the park. “Now, though one is not allowed to touch, one also does not want to touch and harm. Just another sign of changing values in a changing world.”

Demetrios built a lean and unpredictable Marine World, which raised few eyebrows in an era when toddlers roamed free in the backs of station wagons (what’s a carseat?) but seems inconceivable now. In an episode of “The Big Event” podcast that pays tribute to the park, Chronicle education reporter (and 1980s Marine World ride operator) Jill Tucker describes piloting a tourist-filled Tiger Raft Safari boat as a teen, with no previous nautical experience.

“We had a microphone in one hand and you would drive the outboard motor. … No life jackets, no edges to the raft. Like literally anybody could have just tipped over into the murky water,“ Tucker remembers. “Obviously there were no lawyers in 1980 …”

Tucker still calls it “the best job ever,” and in retrospect, it’s hard to disagree.

Marine World seems to have a good half of the Bay Area’s best urban legends. San Francisco 49ers star guard Randy Cross in 1982 severely injured his ankle on a zipline in Whale of a Time World, horrifying Niners fans dreaming of a second straight Super Bowl. When a dolphin named Mr. Spock in 1978 swallowed a shiny metal bolt mistaken for a fish, Demetrios called in Golden State Warriors 7-foot center Clifford Ray to thrust his long arm down the animal’s throat, retrieve the bolt from a stomach, and save the mammal’s life. A Marine World elephant named Mardji put on a bulky costume to play the Bantha steed in the first “Star Wars.”

All of the above gave this enormous amusement park a feel that was the farthest thing from corporate. The people who owned Marine World operated the park like pirates. And as someone who went there, the memories are almost indescribable, because there was no place else like it.

“This really was like a family-run operation, where the employees were incredibly close,” Tucker says. “It’s part of who you are, this place, whether you visited or worked there.”

When the park’s lease was up, the animals were placed on a barge, passing surprised ferry passengers and sailboat captains on the way from Redwood Shores to Vallejo.

Marine World/Africa U.S.A. had one more great moment in the Vallejo location, when actor William Shatner donned a wetsuit and rode a killer whale, to raise money for the California Rare and Endangered Species Preservation Fund. The 5,000-pound, 16-foot orca also leaped over Shatner, and the “Star Trek IV” actor’s perfect description appeared two days later in Herb Caen’s Chronicle column: “It was like nearly being hit by a 747 with teeth.”

By that time, plans for the old Marine World site along Redwood Shores were already in motion. Back in Vallejo, the formerly non-profit Marine World was taken over by corporate owners. And while there are still animals and animal shows at Discovery Kingdom, the superhero-themed rides and steel roller coasters are the clear stars at the park.

The huts were demolished in the late 1980s, and Silicon Valley became a very visible thing. All of the nose-pressed-against-the-glass sights along the Peninsula either were torn down (Burlingame Drive-In, Malibu Grand Prix) or became obscured from the freeway by multi-story office complexes (California’s Great America).

The turnoff was still called Marine World Parkway for more than a decade, even after the shiny cylindrical Oracle office towers rose to the sky. But now those signs are gone too — it’s just Marine Parkway, with so many new buildings, roads and water features it’s hard to tell where the park stood.

But some memories are too strong to be dimmed by rapid change. Marine World/Africa U.S.A. is gone, and yet if anything the legend grows stronger.

Peter Hartlaub is The San Francisco Chronicle’s pop culture critic. Email: phartlaub@sfchronicle.com Twitter: @PeterHartlaub

Listen to “The Big Event” podcast: www.sfchronicle.com/podcasts