Overview

Last seen: April 17, 1989
Location: Her home in Riverton, Wyoming
Age: 41
Current case status: Missing person case investigated as a homicide
NamUs: MP11958

Kathleen Hazel “Kathy” Pehringer disappeared from her Riverton, Wyoming, home on April 17, 1989, while her 14-year-old daughter was at school. Kathleen’s vehicle remained at the residence, but her purse and eyeglasses were gone. There was no apparent struggle and no note explaining where she had gone, something her daughter said was out of character. Kathleen has never been seen or heard from again.

The case was transferred to the Wyoming Division of Criminal Investigation in 2012. Kathleen had already been legally declared deceased in May 1998, and DCI now treats her disappearance as a homicide investigation. Investigators have confirmed that they have identified a person of interest, but the person’s identity has not been publicly released because the investigation remains active.

Detailed Case Breakdown

Kathleen Hazel Pehringer Disappearance: The Unsolved 1989 Riverton, Wyoming Cold Case

Brief Case Summary

Last seen: April 17, 1989
Location: Her home in Riverton, Wyoming
Age: 41
Current case status: Missing person case investigated as a homicide
NamUs: MP11958

Kathleen Hazel “Kathy” Pehringer disappeared from her Riverton, Wyoming, home on April 17, 1989, while her 14-year-old daughter was at school. Kathleen’s vehicle remained at the residence, but her purse and eyeglasses were gone. There was no apparent struggle and no note explaining where she had gone, something her daughter said was out of character. Kathleen has never been seen or heard from again.

The case was transferred to the Wyoming Division of Criminal Investigation in 2012. Kathleen had already been legally declared deceased in May 1998, and DCI now treats her disappearance as a homicide investigation. Investigators have confirmed that they have identified a person of interest, but the person’s identity has not been publicly released because the investigation remains active.

Kathleen Pehringer Vanishes From Her Riverton Home

On the morning of April 17, 1989, Kathleen Pehringer was at the Riverton home she shared with her teenage daughter. Her daughter, Kelly, later recalled seeing her mother at the front door as she left for school. It was the last time she saw Kathleen.

When Kelly returned after school, Kathleen was gone. Her car was still at the residence. No clothing appeared to have been packed, and there was no note saying that Kathleen planned to leave or when she would return.

Kathleen was considered responsible and punctual. She was taking classes at Central Wyoming College and working part-time at the Hilltop Bar. According to case summaries, authorities have believed that she may have willingly left the house with someone she knew but intended to be away only briefly.

Unusual Details Inside the House

One detail remembered by Kathleen’s daughter involved an ashtray in the home. It had apparently been cleaned and contained only two cigarette butts. One appeared consistent with Kathleen’s cigarettes; Kelly believed the second had been smoked by Donald Kenneth Pack Jr., a man who knew Kathleen and had been visiting the home.

Pack reportedly came to the house later on the day Kathleen disappeared and asked where she was. According to Kelly’s account, he then attempted to make a telephone call before leaving.

Some published case summaries state that a diary found after Kathleen disappeared suggested she and Pack were dating. More recent family-supported awareness material specifically corrects that characterization and states that Kathleen was not dating Pack. Because the accounts conflict, it is more accurate to describe Pack simply as a man Kathleen knew rather than state as fact that they were romantically involved.

Donald Pack and the Investigation

Pack had a serious criminal history before Kathleen disappeared. He had previously served a lengthy prison sentence for aggravated rape and kidnapping. Investigators also suspected him in connection with additional sexual assaults committed in Wyoming during the 1970s, although suspicion should not be confused with a criminal conviction in those additional cases.

Years later, Pack again came to the attention of investigators.

While a DCI agent was examining old evidence in connection with the inquiry into Pack and Kathleen’s disappearance, evidence from decades-old sexual assaults was located at the Jackson Police Department. DNA testing eventually linked Pack to two previously unsolved rapes. In 2018, he received another prison sentence for those crimes.

Pack has denied having anything to do with Kathleen’s disappearance.

Equally important, Wyoming DCI has not publicly identified its current person of interest as Pack. The agency has only confirmed that a person of interest exists. Any claim that the unnamed person of interest is definitely Pack would therefore go beyond what investigators have publicly disclosed.

Searches, DNA and a Case Passed Between Investigators

Kathleen’s case has changed hands repeatedly during the decades since she disappeared.

Kelly told reporters that investigators contacted her around 2006 while she was in a treatment facility and obtained a DNA sample. She also recalled being told about a search of property outside Riverton potentially associated with Pack. According to her account, cadaver dogs showed interest in an area where investigators recovered an old buried plastic bag, but usable DNA reportedly could not be recovered from it. These details come primarily from Kelly’s recollection rather than a publicly released DCI investigative report.

Riverton Police eventually transferred the case to the Wyoming Division of Criminal Investigation in 2012. DCI has declined to release the investigative file because the case remains open.

Kathleen Pehringer’s Case Is Now Investigated as a Homicide

The most significant modern confirmation came in 2024, when DCI Commander Ryan Cox publicly stated that Kathleen was declared legally deceased in May 1998 and that the case had been reclassified as a homicide investigation.

Cox also confirmed that investigators have a person of interest and described the investigation as active. DCI encouraged anyone who remembers something about Kathleen, the people around her, or events surrounding April 17, 1989—even information that may seem insignificant—to contact investigators.

No remains have been publicly reported as recovered, no arrest has been announced in connection with Kathleen’s death, and no person has been publicly charged with killing her.

Wyoming’s New Cold Case Database Gives the Case Renewed Visibility

In 2024, Wyoming DCI launched a statewide cold case database intended to improve information sharing between law enforcement agencies and bring renewed public attention to long-unsolved crimes. Kathleen Pehringer’s case was specifically cited as one of the cases receiving renewed visibility through the program.

The public-facing database does not reveal everything investigators possess. DCI has explained that sensitive information—including suspect information—can remain restricted while more detailed records are available to law enforcement agencies working together on cold cases.

That distinction is particularly important in Kathleen’s case because investigators have publicly acknowledged a person of interest without revealing that person’s identity.

Latest Publicly Available Investigation Information

As of August 2026, Kathleen Pehringer’s disappearance remains unresolved. The latest substantial case-specific statement located from investigators continues to describe the matter as an active Wyoming DCI homicide investigation with an identified but unnamed person of interest.

The statewide cold case initiative launched later in 2024 placed Kathleen among Wyoming cases receiving renewed investigative and public attention. Her missing-person record also continues to circulate through current case databases; a Wyoming missing-person compilation updated in 2025 continued to list Kathleen as missing from Riverton since April 17, 1989.

No credible public announcement located through August 2026 reports an arrest, recovery of Kathleen’s remains, identification of the publicly unnamed person of interest, or resolution of the homicide investigation.

Why the Kathleen Pehringer Case Remains Important

Kathleen’s disappearance began with an ordinary school morning and became one of Wyoming’s longest-running unresolved cases. Her car was left behind. She apparently took only a few personal items. There was no obvious evidence of a struggle, no note explaining an extended absence and no confirmed sighting after April 17, 1989.

More than three decades later, investigators no longer treat the case simply as an unexplained disappearance. Kathleen has been legally declared deceased, Wyoming DCI considers the case a homicide investigation, and authorities say they have identified a person of interest.

For Kathleen’s family, however, the central questions remain unchanged: What happened to Kathleen Pehringer, where is she, and who was responsible?

Anyone with information about Kathleen Hazel Pehringer’s disappearance is encouraged to contact the Wyoming Division of Criminal Investigation at 307-777-7181