Mark Himebaugh was 11 when he disappeared from Del Haven, New Jersey, on November 25, 1991. He was last seen around 3:15 p.m. after his mother, Maureen, gave him permission to watch firefighters put out a small brush fire near their home; she left for a short errand and, delayed by rerouted traffic, returned about 40 minutes later to find him gone. He was reported missing at 5:00 p.m.

Mark is described as having red hair and freckles. He was last seen wearing a blue U.S.N. sweatshirt, a gray jacket with a plaid lining, gray Docker-style pants, and white sneakers. The only physical evidence recovered was his left shoe on Sunray Beach about 75 yards from the house and footprints near the tide line; extensive air and ground searches turned up no other trace.

Investigators developed a fractured timeline with unconfirmed sightings that afternoon, including one near a park entrance with an unidentified young girl and reports of him seen with two men, one described as scruffy with a reddish-brown ponytail. In 1993 Thomas Butcavage Jr. was named a person of interest after an allegation involving a videotape, but he was never charged, and some composite sketches do not match him. The case remained open and investigators revisited leads in 2023 using artificial intelligence to analyze accumulated information.

If anyone knew Mark, remembers unusual activity on Sunray Beach that day, or has information that could help, please come forward.