- Marty: "I don't get it, Doc. I mean, how can all this be happening? It's like we're in Hell or something."
- Doc: "No, it's Hill Valley, although I can't imagine Hell being much worse."
- — At Doc's lab in 1985A, after discovering that George McFly was dead.
It was created after an elderly Biff Tannen took the Grays Sports Almanac and stole the DeLorean time machine in 2015, then headed back to 1955 to hand it over to his younger self. As a result, Biff became "the luckiest man on Earth" by successfully betting on everything from horse racing to boxing and amassing a fortune, due to having the results in the almanac.
With Biff in power, history was rewritten to become a totally different 1985 from what it used to be. Hill Valley, once advertised as an idyllic and ideal place to live, became a literal hell on Earth, overwhelmed by skyrocketing crime, murders, drive-by shootings and corrupt officials. The high school was burned down and never rebuilt; armed gangs drove through the neighborhoods terrorizing and even killing some of the residents; the public library was shut down and boarded up; and the old courthouse was turned into a gaudy casino-hotel named Biff Tannen's Pleasure Paradise Casino & Hotel, which drew in unsavory types of all kinds. Indeed, Marty McFly initially thought he really was in Hell when he found the changed timeline. Emmett Brown, however, was of the opinion that Hell couldn't be much worse.
- Hill Valley in 1985 was a town in chaos, as Biff had taken over most of the land in Hill Valley, as well as ownership of the Hill Valley Police Department, through his corporation BiffCo.
- Biff was married to Lorraine Baines McFly, as he had secretly murdered George McFly in an alleyway in 1973.
Biff subsequently framed Red the Bum for the murder by having one of the members of the Hill Valley Police Department plant George's stolen wallet on the innocent street vagrant.
- Dave McFly was in prison, having been run out of town by the Hill Valley Police Department, under Biff's orders, in 1981. He had a tough time alone, eventually resulting in his incarceration.
- Marty McFly had been sent to a boarding school in Switzerland.
- Linda McFly had financial problems, and owed the bank a substantial amount of money. (Biff threatened to cancel Linda's credit cards and let settle her debts by herself if Lorraine left him.)
- Emmett Brown shut down some of his higher brain functions, in the manner of a practice performed by some Eastern religions, appearing as if he was lobotomized, and was being kept in the County Asylum.
- Hill Valley High School burned down in 1979, and by 1985, still hadn't been rebuilt.
- Richard Nixon was on his fourth term as President of the United States, rather than Ronald Reagan.
- Biff Tannen's Pleasure Paradise Casino & Hotel is a 27-story tall hotel built on the site of Hill Valley's dilapidated courthouse. A display for the Biff Tannen Museum is located to the right of the hotel entrance.
- Oak Park Cemetery is where George McFly was buried in 1973, and is within sight of a BiffCo refinery. Marty and Doc both know the location of the cemetery, suggesting that it also exists on the site in 1985.
- The Strickland residence is a rundown house within a short distance of the burnt-out remains of Hill Valley High School, and is the home of former principal Mr. Strickland who, armed with a shotgun and wearing a bulletproof vest, fights a one-man war against the armed teenage gangs — 'slackers' — who are driving around the streets, terrorizing and even killing some of the residents. He believes Marty McFly (who he does not recognize, due to history having been changed) to be the slacker responsible for stealing his newspapers.
- The counterpart in 1985A to 1985's Courthouse Square is a set of businesses around the Paradise Casino.
Among those that were recognizable are:
- Dee Dee's Delight, on the site of Gaynor's Hideaway. The tavern advertises that it has "nude barmaids".
- A Biffco toxic waste reclamation station, at the site of a Sherwin-Williams paint store .
- Hell Hole, a specialized club, formerly the site of the Hill Valley Stationers.
- Bangkok, another club, formerly the site of the closed Elite Barber Shop.
- The closed Bluebird Motel is divided in two businesses: a place advertising a peep show and hardcore pornography in the left side of the buiding and a pawn shop in the right side.
- Bad Rap Bail Bonds is located in the building with the open stairway occupied by Orson and Tillich, Attorneys at Law in 1955.
- Tanya's, a house of prostitution, is on the site of the former Ruth's Frock Shop.
- PIG Mart, a store that sells adult books and "love tools" is at the site of Statler Studebaker.
- Hill Valley Theater of Live Sex Acts at the site of the Essex Theater.
- The War Zone where Lou's Cafe had been in 1955, or Lou's Aerobic Fitness Center in 1985.
- Time to Shoot, which advertises "24-hour photos" is next door, located at the site of Blast from the Past, where Marty had purchased the almanac.
- French Fantasies, on the site of Broadway Florist.
- Sin, located in the former Lawrence Building.
Alternate timeline of events
For years in this timeline before and after 1985, see the Hell Valley timeline.
- Saturday, October 26: Doc, Marty, Jennifer and Einstein arrive back from original 2015 at 9:00 p.m. and eventually find out that things have changed. Marty finds a random African-American family living in the McFly residence and meets the alternate versions of his mother and Biff.
- Sunday, October 27: Marty finds out the truth about Biff and the almanac and narrowly escapes an enraged Biff. Marty and Doc head back to 1955 at 2:42 a.m. to put history back on track.
Behind the scenes
- The elaborate set of Courthouse Square in 1985A was visible for no more than 60 seconds in Part II. Photos of the various locations were not released until 2010 as part of the Blu-ray edition of the trilogy.
- Robert Zemeckis and Bob Gale have both said that director Frank Capra was one of the persons whom they admired, and the "Hell Valley" sequence is reminiscent of "Pottersville", the alternate reality in Capra's classic 1946 film, It's a Wonderful Life.
- Downtown Hill Valley in 1985A and downtown Hill Valley in 1985 have many of the same types of businesses. In both timelines, a person downtown can buy alcohol, watch X-rated films, purchase "adult" books and toys, pawn their possessions, and arrange for a bail bond to be released from jail, although it's more pronounced in 1985A.
- Doc comments "I can't imagine hell being much worse." Ironically, the center of this particular hell is called "Paradise".
- The graphic novel Watchmen takes place in an alternate 1985; like in the Biffhorrific timeline, the Watergate scandal was not revealed, and Nixon was under his fourth term, being the U.S. President instead of Ronald Reagan well into the 1980s.
- With the election of Donald Trump, on whom Biff Tannen of 1985A was based, some hardcore BTTF fans are scared this reality might actually happen, albeit post-2015.
- Back to the Future Part II
- Back to the Future Part II novelization
- Back to the Future Part II & III
- Super Back to the Future Part II
- Back to the Future: Biff to the Future
- Back to the Future: The Official Book of the Complete Movie Trilogy (on Biffhorrific 1985)