Key facts
- Name: Nyleen Kay Marshall (née Briscoe)
- Born: September 18, 1978, Orange, California
- Age at disappearance: 4
- Last seen: June 25, 1983, ~4:00 p.m.
- Location: Beaver dams on Maupin Creek, Helena National Forest, Elkhorn Mountains, near Clancy, Montana
- Height / build: 3’2″, brown hair, blue eyes
- Status: Still missing — classified as non-family abduction
- Investigating agency: Jefferson County Sheriff’s Office
“Follow the shadow”
The picnic was a ham-radio club outing — the Capital City Radio Club, a sunny Saturday in the Elkhorn Mountains, families spread out near Maupin Creek in the Helena National Forest. Four-year-old Nyleen Kay Marshall was playing with a group of older children near the beaver dams.
Around 4:00 p.m., the older kids walked ahead. Nyleen fell behind. When they turned around, she was gone — last seen sitting alone near the water.
The children told a strange story. A man in a purple jogging suit had been nearby. He had spoken to Nyleen. He had tried to get her to play a game he called “Follow the Shadow.” The man in the purple jogging suit has never been identified.
Ten days of intensive searching followed — the FBI, hundreds of volunteers, divers, cadaver dogs, members of the local LDS Church. No physical trace was ever found. No clothing, no sign of a struggle, no sign of an animal attack.
Who Nyleen was
Nyleen Kay Briscoe was four years old, the daughter of Nancy Marshall, living near Clancy, Montana. Her stepfather was Kim Marshall. Forty-three years later, the public record of her short life is thin — a few photographs, a physical description, the terrible fact of the picnic. Her mother died in 1995; it was reported she was sexually assaulted and murdered in Mexico. Her stepfather was at one point considered a person of interest in Nyleen’s case; he was never charged, and the presumption of innocence stands.
The calls and the letter
Two years after the picnic, the case took a turn that still chills investigators.
In November 1985, the National Center for Missing & Exploited Children began receiving anonymous calls from a man who said he had abducted Nyleen. Police traced the calls to payphones in Edgerton, Wisconsin — and the calls stopped as soon as the booths were identified.
Then, in January 1986, a typewritten letter arrived at Child Find, a New York-based missing-children’s organization. The writer said he had picked up “a girl named Kay” on a road in Elkhorn Park, between Helena and Boulder, Montana, and had decided to take her home with him. The letter was postmarked Madison, Wisconsin — thirty miles northwest of Edgerton.
The letter included details about Nyleen’s case that had never been released to the public. The writer explained that he had a good investment income, worked from home, and homeschooled Kay. He traveled frequently with her — all over the United States, in Canada, in Great Britain. He said he loved the child and she was happy, and that although he knew her family missed her, he could not “let her go.” The calls and letter indicated sexual abuse.
The writer was never identified. It was never established whether he actually had anything to do with Nyleen’s disappearance — or whether he was a cruel fantasist who had studied the case closely enough to fake inside knowledge. Both readings remain on the table, and investigators have never resolved which is true.
There were other threads over the years: reported sightings (a Wisconsin restaurant, a New Orleans hospital), false confessions. All dead ends.
The investigation
The case is classified as a non-family abduction — the official judgment being that Nyleen did not wander off and was not taken by a relative. The search in 1983 was one of the largest Montana had seen. The Unsolved Mysteries segment and Nancy Grace coverage kept the case in the national eye. Age-progressed images have been released over the decades.
In 2026, with renewed media coverage and NCMEC reviews, the Jefferson County Sheriff’s Office still takes tips. No solid lead has ever emerged. The man in the purple jogging suit, the caller from the Edgerton payphones, the author of the Madison letter — none has ever been found.
Theories: what might have happened
Forty-three years, and the case still turns on two unidentified men who may be the same man, or may be no one at all.
Abduction by the man in the jogging suit. The children’s account is the only eyewitness thread: a stranger, a game called “Follow the Shadow,” a four-year-old who vanished within minutes. The 1985–86 caller and letter-writer fit this shape — someone who took a little girl and kept her. The non-public details in the letter are the strongest argument that the writer was genuine. Against it: no one ever identified the jogger, the caller, or the writer, and a determined hoaxer with access to unreleased details cannot be ruled out.
A wilderness accident. A four-year-old alone near a creek in mountain forest — drowning, exposure, a fall. The argument for it is circumstantial plausibility. The argument against is the search: ten days, divers, dogs, hundreds of people, and not a thread of clothing recovered. Children lost in the woods leave traces. Nyleen left none.
Family involvement. The stepfather was considered a person of interest early on. There is no public evidence tying him to the disappearance, he was never charged, and the case’s official classification is non-family abduction. This theory survives mostly as a question, not as evidence.
The letter-writer as hoaxer. That the calls and letter were the work of someone who never had Nyleen — someone who taunted her family and investigators from Wisconsin payphones for reasons of his own. The cruelty of the letters, with their claims of love and travel, fits a fantasist’s profile uncomfortably well. But the unreleased details cut the other way. Investigators have never been able to close this question, which is why the case still aches.
Have information?
Contact the Jefferson County Sheriff’s Office: 406-225-4075. You can also contact the National Center for Missing & Exploited Children: 1-800-843-5678 (reference #601812). In an emergency, dial 911.
Timeline
- September 18, 1978 — Nyleen Kay Briscoe is born in Orange, California.
- June 25, 1983, ~4:00 p.m. — Nyleen vanishes from a family picnic near the beaver dams on Maupin Creek; children report a man in a purple jogging suit.
- June–July 1983 — Ten-day intensive search (FBI, volunteers, divers, dogs). Nothing found.
- November 1985 — Anonymous caller tells NCMEC he abducted Nyleen; calls traced to Edgerton, Wisconsin payphones, then stop.
- January 1986 — Typewritten letter to Child Find claims the writer has “a girl named Kay”; postmarked Madison, Wisconsin; contains non-public details.
- 1995 — Nyleen’s mother dies.
- 1980s–2000s — Unsolved Mysteries and Nancy Grace coverage; sightings and false confessions ruled out.
- 2026 — Renewed media coverage; NCMEC review; Jefferson County still takes tips.
- Today — Still missing.
FAQ
Is Nyleen Marshall still missing?
Yes. As of October 2026, Nyleen Marshall has been missing for more than 43 years. The case is classified as a non-family abduction and remains open.
What was the “Follow the Shadow” game?
According to the children she was playing with, an unidentified man in a purple jogging suit spoke to Nyleen and tried to get her to play a game he called “Follow the Shadow” shortly before she vanished. The man was never identified.
Who wrote the letters claiming to have Nyleen?
Unknown. In 1985–86, an anonymous man called missing-children’s organizations and sent a typewritten letter claiming he had abducted Nyleen and was raising her. The calls were traced to Wisconsin payphones; the letter was postmarked Madison, Wisconsin. The author was never identified, and it was never proven he had her.
Was Nyleen Marshall ever found?
No. No trace of Nyleen has ever been found, and reported sightings over the decades have all been ruled out.
How old would Nyleen Marshall be today?
Nyleen was born September 18, 1978 — she turned 48 in September 2026.
How can I help?
Share this case file and her age-progressed images. Anyone with information should contact the Jefferson County Sheriff’s Office at 406-225-4075 or the NCMEC at 1-800-843-5678.
Sources
- Official / law enforcement: Jefferson County Sheriff’s Office; National Center for Missing & Exploited Children (#601812).
- News: Independent Record (Helena, archival 1983 coverage).
- Reference: Wikipedia, “Disappearance of Nyleen Marshall” (retrieved Oct 2026); The Charley Project, “Nyleen Kay Marshall”; Locations Unknown, “Nyleen Kay Marshall.”
- Media: Unsolved Mysteries (NBC segment); Inhuman: A True Crime Podcast, Episode 489 (2024).
Found an error? Tell us via the About page and we will fix it promptly and note the change here. Last verified October 2026.