Overview

Last seen: August 12, 1975 — Oshkosh/Town of Menasha area, Wisconsin. The reported drop-off location was U.S. 41 at former State Highway 150, now the Interstate 41/County Highway II area of Fox Crossing.

Circumstances: Bonnie, 33, was separated from her husband and staying with her sister. She went to taverns in the Neenah and Oshkosh area with her estranged husband. He told investigators they argued during the return trip and that Bonnie got out near the highway and walked toward home. Investigators said no independent witness confirmed the reported drop-off and no credible sighting of Bonnie was established afterward. Authorities believe she is deceased, but her remains have not been recovered and no one has been charged.

Detailed Case Breakdown

Bonnie Marie Repinski: The Unsolved 1975 Wisconsin Disappearance

Bonnie Marie Repinski was 33 years old when she disappeared in Wisconsin in August 1975. More than five decades later, her whereabouts remain unknown, and investigators believe she is deceased. What began as a missing-person investigation has become one of Winnebago County’s longstanding cold cases.

Bonnie Repinski Was Separated From Her Husband

In the months before her disappearance, Bonnie had been living in Sheboygan, Wisconsin, but had separated from her husband, David R. Repinski, and filed for divorce. While the divorce was pending, she moved in with her sister in the Town of Menasha.

Bonnie was the mother of three children. She was described as approximately 5 feet 6 inches tall and 120 pounds, with brown hair and brown eyes.

The Night Bonnie Repinski Disappeared

On August 12, 1975, Bonnie went out with her estranged husband. According to information David later gave investigators, the two visited several taverns in the Neenah and Oshkosh areas. The outing was reportedly intended to celebrate Bonnie’s birthday and give the couple an opportunity to discuss their pending divorce.

As they traveled back toward the Town of Menasha residence where Bonnie was staying, David told police that an argument occurred.

According to his account, Bonnie asked to get out of the vehicle near U.S. Highway 41 and the former State Highway 150. The location is now described as the area of Interstate 41 and County Highway II in Fox Crossing.

David said Bonnie began walking in the direction of her sister’s home.

She was never seen or heard from again.

No Witness Confirmed Bonnie Was Dropped Off

A major difficulty in reconstructing Bonnie’s disappearance is the lack of an independent witness to her reported final moments.

Winnebago County Sheriff’s Office Detective Chris Braman told Neenah News in 2023 that investigators had never located a witness who could confirm seeing Bonnie get out of the vehicle along the highway. Investigators also had no credible sightings of Bonnie afterward.

That means the account of Bonnie leaving the vehicle could not independently be verified.

Authorities initially considered the possibility that Bonnie voluntarily left and began a new life. However, she left three young children behind, and members of her family suspected foul play.

Investigators Believe Bonnie Is Deceased

The case presents another major challenge: Bonnie’s remains have never been recovered, and investigators have not identified a crime scene connected to her disappearance.

In 2023, Detective Braman said investigators believed Bonnie was deceased but explained that the absence of a body, confirmed crime scene, physical evidence and witnesses had made the case particularly difficult to solve.

Authorities have considered multiple people during the investigation. Braman said Bonnie’s husband received close scrutiny because he was the last known person to report seeing her. He also stated that other people had been considered and interviewed over the years.

No one has been charged in connection with Bonnie’s disappearance, and publicly available records do not establish that any particular person caused her disappearance.

Cold Case Investigation Renewed

In August 2023, the Winnebago County Sheriff’s Office renewed public attention on Bonnie’s disappearance and announced that detectives were actively working the nearly 50-year-old case.

Investigators appealed directly to anyone who might possess information, including details a witness might consider insignificant.

The appeal produced new information. Detective Braman told Neenah News that at least two people came forward who apparently had never previously been contacted by law enforcement.

Investigators expressed hope that the passage of time might persuade someone with knowledge of Bonnie’s disappearance to finally speak.

No publicly announced arrest, recovery of Bonnie’s remains or resolution of the case has followed that renewed appeal.

Bonnie Repinski’s Case Today

Bonnie remains listed by the Wisconsin Department of Justice Clearinghouse for Missing & Exploited Children & Adults. The state’s official record lists her as missing since August 12, 1975, from the Town of Menasha in Winnebago County and identifies the Winnebago County Sheriff’s Office as the investigating agency.

Her case is also recorded in the National Missing and Unidentified Persons System under NamUs case MP57021.

The Doe Network added Bonnie to its missing-person database in December 2024 as case 4948DFWI, providing another avenue for keeping her disappearance visible to researchers and the public.

More than 50 years after Bonnie vanished, the fundamental question remains unanswered: what happened after she went out with her estranged husband on August 12, 1975?

For investigators, even a seemingly minor memory from someone who was in the Neenah, Oshkosh, Menasha or Fox Crossing area in August 1975 could potentially provide information that was never documented during the original investigation.