Celeste Wyma Hensley Greub, 20, of Casper, Wyoming, was last seen on August 10, 1976, in the Cloud Peak Wilderness of the Bighorn Mountains, Johnson County, Wyoming, while camping near Misty Moon Lake with her aunt, Celeste Wyma Dale, and family friend Sigrid Howe. Greub said she was tired and stayed to rest on the trail while the other two women continued toward the summit of Cloud Peak; when they returned around 5 p.m., she was gone. She was not carrying food, water, or other supplies — only a pocketful of candy. She is described as 5'2", 115 to 120 pounds. A hiking party reported a possible sighting the following day of a woman matching her description walking normally near an unnamed lake between Misty Moon Lake and Gunboat Lake, near Florence Pass, though this was never confirmed as Greub.
A search involving 200 to 300 people — including local search and rescue, out-of-state volunteers, military dog handlers from F.E. Warren Air Force Base, and aircraft — covered roughly 80 square miles over more than two weeks without locating her; her family reportedly spent $15,000 to $20,000 to help fund the effort. Early reporting speculated Greub may have left voluntarily amid rumored marital problems; her family and her husband have disputed this account, and it was subsequently corrected in later reporting. Her original missing-person case file, if one existed, was destroyed in a water-damage incident affecting pre-1977 Johnson County Sheriff's Office records, and she was not entered into the FBI's National Crime Information Center database until the Johnson County Sheriff's Office initiated a delayed entry in late 2025. Some individuals connected to the original search, including a former lead searcher, have theorized Greub may have drowned or been placed in Misty Moon Lake, though the lake has never been searched and no physical evidence currently supports this theory. The case remains open with the Johnson County Sheriff's Office. Case Number 18S0075.