Michael J. Fox suggested it would be fun to visit the Old West and the final installment in the Back to the Future trilogy was born. It's Back to the Future Part III, the movie that gave us a "Mad Dog" and a happy ending for Dr. Emmet Brown. Today, we look at 10 things you missed in Back to the Future Part III.

The Paradox script.

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Paradox Back to the Future script

Despite the cliffhanger ending, there were originally no real plans for a Back to the Future sequel. However, once the studio became dead set on making one, director Robert Zemeckis and co-creator Bob Gale agreed to come back to make it. Conceived as a single sequel, a script called Paradox contained elements that were eventually split into II and III. Paradox remained the working title for the sequel shoots and parts of that script were used in the novelizations of the two movies.

Marty's bail.

Marty's Back to the Future Bail

An even earlier version of the sequel story, predating Paradox, saw Marty traveling back to the 1960s. He's arrested because he doesn't have a draft card. Lorraine bails him out and as a result she no longer has the money necessary to travel to San Francisco to meet George to celebrate their anniversary. As Doc says in that version of the script, this was supposed to be the night that the McFly parents, "Engage in biological reproductive mating behavior." Had producers stuck with this version of the sequel story, we most likely wouldn't have even visited the Old West.

Doc's shirt...

Doc's Back to the Future 2 shirt

As most fans know Back to the Future II and III were filmed back-to-back, a then relatively unprecedented move for a major movie studio. Doc Brown wears a shirt through the majority of the second movie with illustrations of trains and cowboys on horses: an awesome bit of foreshadowing for the events of Back to the Future III.

Fake Hill Valley, real lightening.

Back to the Future lightning

Back to the Future III was allowed to film in Sonora, California rent-free under one condition: they had to agree to leave all of those cool Old West buildings there, in hopes that the sets would serve as an attraction for other Western themed productions to come and film there. Universal Studios agreed, taking only the Clock Tower when they left. The county itself served as the site for Gary Cooper's For Whom the Bell Tolls, Gregory Peck's The Big Country, Clint Eastwood's Unforgiven, and TV shows like The Lone Ranger, Rawhide, Gunsmoke, Bonanza, and Little House on the Prairie. Six years after the release of Back to the Future III, the movie sets sadly burned down, in a 7000-acre fire started, like many fires, by a bolt of lightning.

The Clint Eastwood joke.

Back to the Future 3 Clint Eastwood jokes

Speaking of Clint Eastwood, there's a great Clint Eastwood joke at the drive-in theater. (Doc replies: "Who?") But even better, there's a subtle visual gag involving Eastwood, as well. As Marty emerges from the bathroom in his cowboy getup, two of the posters on the wall are from b-movies that featured a then-unknown Eastwood.

Michael J. Fox passed out in the noose.

Noose Back to the Future 3

As detailed in the actor's autobiography, Lucky Man, Michael J. Fox went unconscious during a dangerous stunt gone wrong, blacking out as the rope actually began to choke him during the scene where "Mad Dog" Tannen tries to lynch Marty.

The clock tower.

Back to the Future 3 Clock Tower

As Marty and Doc talk to the conductor, the clock for Hill Valley's all-important Clock Tower can be seen getting unloaded from the train in the Hill Valley of 1885.

Frisbees really were around in 1885.

Frisbees Back to the Future 3

In another of the movie's many great visual gags, Marty throws a "Frisbie's" pie plate in Back to the Future III, knocking a gun out of Mad Dog's hand. The Frisbie Pie Company was a real thing, started in 1871. College students tossing their empty pie pans around did, in fact, lead to the eventual creation of the modern Frisbee.

Michael J. Fox convinced ZZ Top to perform an on-set concert.

ZZ Top Back to the Future 3

Hit making rock trio ZZ Top cameos in Back to the Future III, playing an old-timey version of the song "Doubleback," which later appeared on their Recycler album. As legend has it, Michael J. Fox asked the boys if they would play a rendition of "Hey Good Lookin'" while the production waited for a camera to be repaired. ZZ Top obliged, which turned into a bit of an on-set party, as song after song followed.

Ronald Reagan could've been the mayor.

Ronald Reagan Back to the Future 3

("Ronald Reagan? The actor?!") Then President Ronald Reagan so much enjoyed the joke about him in the original Back to the Future he reportedly asked to have the projectionist rewind the scene so he could hear it again. He even gave the movie a shout-out in his 1986 State of the Union address. Producers him offered him the role of Hill Valley's mayor in Back to the Future III, which was released a little over a year after Reagan left office, but he declined. The two-term Governor of California wasn't interested in returning to Hollywood, unlike one of his successors (Arnold).