Friday the 13th:
A Chronology of the curse of crystal lake
By Jasonlivessince1980
September 1930: Pamela Sue Voorhees, maiden name unknown, is born (Evidence: tombstone in part 4 gives birth year and color of birthstone on class ring in part 1 during decapitation indicates a sapphire).
1935: The Christy family opens Camp Crystal Lake in rural Crystal Lake, NJ, a few miles from the PA border. (Evidence: The famous 'Camp Crystal Lake' sign). 
June 13, 1946: Jason Voorhees born to Pamela & Elias Voorhees in Crystal Lake, NJ. Elias leaves the teenage Pamela shortly thereafter, but she never changes her name. Psychopathic tendencies begin to emerge in young Pamela. Jason suffers from a variety of birth defects, including alopecia, retardation, limited linguistic capability and severe craniofacial deformity. Pamela takes Jason, who she keeps mostly hidden from contact with the outside world, and moves around the NJ/PA area, taking odd jobs wherever she can find them, living at the YMCA and dingy apartments (Betsy Palmer's conceptualization of Pamela given in CLM; date of Jason's birth given in part 1 and year given in JGTH).Circa 1950: Diana Voorhees born to Elias Voorhees and an unnamed second wife.
1950's: Pamela Voorhees moves back to Crystal Lake and takes a job as a cook at Camp Crystal Lake. Jason is an athletic youngster but fearful of other children and often keeps his face hidden. Pamela ensures he kept isolated from other children, never attends school (according to Ginny in part 2) and insists must be watched apart from the others by specially appointed counselors. Life settles into relative comfort for mother and son, despite obvious challenges.
Summer 1957: Jason drowns in Crystal Lake at age eleven while the two counselors assigned to watch him are off exploring each other's naughty bits. Pamela is enraged and vows revenge for their irresponsible behavior.
July 4, 1958: 28-year-old Pamela murders counselors Claudette and Barry at the camp, which is subsequently closed down (date from Victor Miller's original script). Attempt to reopen in 1962 by Christy family fails due to bad water, further reinforcing the ominous reputation of the camp. Mr. Christy does nothing with the property thereafter, which falls into a state of disrepair. Around this time the locals begin to call the place "Camp Blood."
June 13, 1975: On Friday the 13th, Pamela Voorhees, age 45, returns and slaughters the new camp counselors at the almost-reopened Camp Crystal Lake, recently purchased by Steve Christy (1943-1975) from his parents. Pamela Voorhees is decapitated by young counselor Alice Hardy. Alice later claimed to have been attacked by Pamela's son as she sat in a boat on the lake. Curiously, her head is never recovered and her headless body is buried in an unmarked grave in a small rural cemetery a few miles outside the camp. In 1979 her former husband, Elias purchases a gravestone which, possibly due to hastily written instructions, ends up with a typo death date. After Jason's bloody rampage five years later, her head was located in his possession and interred with the body.
August 1975: Alice Hardy, only survivor of Mrs. Voorhees' murderous rage, disappears from her home in Crystal Lake. Locals speculate she may have gone back to the scene of the murders to find some closure and contemplate "the boy" who attacked her. Unbeknownst to Alice, the boy may have been watching, and followed her to her own house where she was murdered. According to legend, "there was blood everywhere."
1978: Christine Higgins, age 17, has a brief encounter with a "hideous looking man", commonly believed to be Jason Voorhees, out in the forest near her family's farm house in Green Valley, NJ. She survives, but doesn't remember how. This is Jason's first known attack on a person other than his mother's killer, though in this case he stopped short of murder.
June 13-16, 1980: Jason Voorhees, age 34, emerges from the woods to murder several camp counselors at a counselor training center on the fifth anniversary of his mother's death. Two later murder sprees at Higgins Haven and a summer home a few miles from the camp leave dozens dead, including the killer himself, who suffers a fatal head wound at the hands of 12-year-old Tommy Jarvis. Tommy is plagued by post-traumatic stress, hallucinations and severe anxiety and begins taking a variety of medications, including Thorazine, Ritalin, Valium and Percodan. (medication list in 'A New Beginning' indicates Jarvis began his medications in April 1978, possibly due to trauma of parents' separation, which of course increased substantially after his encounter with Jason) It is publicly stated that Jason's body was cremated, although he was secretly buried in an unmarked grave in Eternal Peace Cemetery a few miles outside of Crystal Lake. Some years later a headstone was purchased for him by Elias Voorhees.
July 1985: Deranged paramedic Roy Burns is killed by seventeen-year-old Tommy Jarvis after a bloody killing spree at a halfway house while impersonating the late Jason Voorhees. (Jarvis's medication list mention a "doctor review" in "July 1985" as the final entry, presumably right before his transfer to the halfway house.) Tommy, still mentally unstable, flips out after the incident and temporarily believes he is Jason, seriously wounding a health worker.
June 12, 1986: After having been released from a mental hospital, Tommy Jarvis, age 18, and friend Allen Hawes exhume Jason's grave. The killer rises from his tomb and resumes his killing spree at Camp Crystal Lake, now reopened as Camp Forest Green, before being chained to the bottom of Crystal Lake the following evening by Jarvis in an attempt to satisfy a metaphysical need for Jason to return to his original grave in order to rest in peace. The only surviving adults, Tommy and Megan send the children home and never tell the police that Jason is in the lake.
October 13, 1986: Ten-year-old Tina Shepard's father, John dies when the dock he was standing on collapses from her psychokinetic anger. Tina spends the next several years in and out of mental hospitals as she copes with her guilt. Jason is still chained underwater for the next six years. Around this time Camp Forest Green/Crystal Lake is shut down for good and the cabins are finally torn down (Stephen tells some campers that the cabins were torn down "a few years ago" in Jason Goes to Hell).October 1992: Tina Shepard defeats a resurrected Jason with her telekenesis at age 16. (Quote from John Carl Buechler stating the span of time between Mr. Shepard's death and the Jason murders was about six years to his mind in CLM), but not before Jason murders 14 vacationers.
June 1993: Jason Takes Manhattan. After committing multiple homicides on a cruise ship and stalking the remaining boat occupants through the streets of New York, Jason is severely burned by toxic waste in the sewers. He finds a new wardrobe and mask and walks fifty-three miles through the countryside back to Crystal Lake, NJ.
August 4, 1993: Jason Goes to Hell. The FBI have been aware of the legend of Jason Voorhees for some time, but facing stonewalling by local authorities and a lack of evidence had always blamed copycat killers. Having investigated the murders in New York, the feds tracked Jason back to his native haunts, where they ambush him on August 2, 1993 and destroy him with a mortar attack. (Jason's coroner's tag gives this date, according to a rare photo in the official JGTH magazine). Jason subsequently body hops until he is reborn through the body of his sister Diana, then killed by his niece Jessica Kimble with a specially forged dagger designed to destroy the curse that keeps Jason earthbound. He is dragged to Hades by demons where he remained until his resurrection by Freddy Krueger in 2003.
