The morning of Saturday, March 15, 1969 was a warm one in Boulder, Colorado—fifty-two degrees, breaking a weeklong streak of freezing weather. In the University Hill neighborhood, the sun rose and illuminated the home of CU Boulder Russian History Professor Thomas Riha. Inside, his table was set neatly for a breakfast that would never happen. Thomas’s phone began to ring. It would ring all day. Thomas Riha would never answer that phone again. 

This is the tumultuous true story of a missing professor, a mysterious woman, a controlling FBI director, and their tangled webs of national and international intrigue. Cyanide poisonings, profound grief, a US intelligence communication crisis, and a Senate investigation lay ahead, but on the quiet morning of March 15, no one fathomed this would become an infamous Colorado cold case.

The History Student

Thomas Riha’s story begins thousands of miles away from Boulder. Thomas was born in Czechoslovakia on April 17, 1929, and grew up in a flat in the shadow of Prague Castle. His mother Ruth was Jewish, and after Germany invaded Czechoslovakia in 1939, she was forced to flee to California with Thomas’s maternal grandparents. Thomas lived with his father’s extended family in the Czech countryside during World War II, and then, after graduating high school, followed his mother to California in 1947 and enrolled at the University of California, Berkeley. Known as Tom to his many friends, he was a popular student who learned multiple languages, joined the YMCA, and passionately studied Russian political history. Riha’s grandparents paid for his schooling but did not provide any extra funds. He worked multiple jobs and earned a reputation for frugality. 

After graduating with his BA in political science in 1951, Thomas began working on his MA and became a naturalized US citizen in December 1952. He then joined the US Army and served at Fort Bragg in North Carolina. Riha was likely involved in translation work occurring at Fort Bragg as he was fluent in English, French, German, Czech, and Russian.

Thomas was discharged as a Specialist 3rd Class in December 1955 and received his MA from Berkeley in 1957. He was working on his PhD in Russian history in 1958 when he received a Foreign Area Training Fellowship from the Ford Foundation. Riha was studying Russia’s constitutional regime of 1907–1917, and the fellowship funded a year of research in Russia. There was just one problem: it was the height of the Cold War.

A Trip to the USSR

The capitalist United States and the communist Union of Soviet Socialist Republics (USSR) had been vying for global dominance since 1947. The Central Intelligence Agency (CIA) and Federal Bureau of Investigation (FBI) were on high alert for Soviet agents at home and abroad. The Russian Komitet Gosudarstvennoy Bezopasnosti (KGB) and Czech Státní bezpečnost (StB) were in the midst of recruiting their own networks of Cold War spies.

Against this backdrop of global political tension, Riha’s fellowship grantors were concerned about his Czech background. They gave him the fellowship on the condition that he not visit Czechoslovakia while abroad. He agreed—then immediately made plans to visit his family in Czechoslovakia. From a now-declassified Boston FBI interview conducted in 1960 after Riha returned to the United States, we know the CIA briefed Riha when he landed in Paris on June 21, 1958. Riha claimed he was never contacted by the CIA again. However, the CIA intercepted eleven letters between Riha and the Soviet Union from 1958 to 1963, making it likely they were suspicious of his activity and may have believed he was involved with foreign intelligence services.

Some of Riha’s interactions while abroad were indeed suspicious. After he arrived in Prague in summer 1958, Riha was approached by a government agent named Karel Chrpa. Chrpa offered to give Thomas a tour and stationed himself outside Riha’s family home. While Thomas claimed he did not engage with Chrpa, Thomas’s nephew Zdenek Cerveny remembered Riha accepting rides from Chrpa. Thomas left Prague on July 12, 1958, traveled back to Paris, and received a postcard there from Chrpa. Thomas arrived in Russia on September 27, 1958, where he studied at Moscow University and traveled freely across the country. He met a likely KGB agent named Iurii Mikhalkov who invited him to a luxurious dinner at a hotel. Because Mikhalkov had money and a car, Thomas assumed he was associated with the Russian government, but claimed he only dined with him once. 

Despite these encounters with probable Soviet agents, Riha insisted in his FBI interview that he was loyal to the United States. The Boston FBI considered using Riha as a double agent, but decided against it: “It is not believed at this time that RIHA possesses any double agent potential.” Riha had received a professorship at the University of Chicago. “In this position [Riha] will have no reason to institute contact with the Soviets,” concluded the report. 

After he returned to the United States in August 1959, Thomas moved to Chicago in 1960. He edited Readings in Russian Civilization Volumes I–III, published in 1964. Everything seemed to be going well: an excellent job, newly edited books, a wide circle of friends. University publications show Riha was a popular professor. He spent a year as a visiting professor at the University of Marburg in West Germany, visiting Russia for a second time.

Then, sometime between 1960 and 1967, he met the woman who would later become a prime suspect in his disappearance. Going by the name Galya, she worked for an art company designing graphic layouts. They may have met because they ran in similar artistic circles, as  Thomas used a nearby publisher for his book design. According to Galya, she and Thomas became fast friends—and more. It is impossible to determine exactly where and when Thomas and Galya met, but she would become inextricably linked with the professor’s later disappearance.
 

From Gloria to Galya 

Galya was born Gloria Forest on March 30, 1931, in Chicago, Illinois. Gloria recorded her personal history in a series of journals around 1970, which revealed she had a traumatic childhood. “Very scared, very unhappy—very very lonely,” Gloria recalled. She claimed her family would often lock her in the basement. Gloria remembered talking to imaginary friends to survive. At church, she would pretend the statues above the altar would come alive and speak to her. 

Gloria attended Catholic schools and possessed great artistic talent. She married a bandleader named Robert McPherson when she was sixteen and became Gloria McPherson. However, Robert became abusive and targeted their newborn baby. In her journals, Gloria claimed she forged a signature on one of Robert’s checks and attempted to cash it in order to survive. She was arrested and placed on probation for forgery. 

Gloria then moved to her parents’ hometown of Galva, Illinois. She started telling townspeople she worked for the FBI after a neighbor taught her how to shoot a gun in April 1951. Soon after, the FBI investigated her for impersonating an agent. The case was closed because she hadn’t financially benefited from the impersonation. She went on to work as a bookkeeper for the town of Wellston, Illinois, and was arrested twice in 1954 for forging three thousand dollars worth of checks endorsed with the forged signatures of Wellston’s mayor and treasurer. 

Gloria may have been an FBI informant during this time. She uncovered evidence of illegal activities in Wellston in June 1954, when she caught Wellston’s mayor tampering with ballots during an election and contacted the FBI. In October 1955, she served as a witness against a ring of city employees charged with a jewel theft. During her testimony, she checked into a hotel, requesting a hotel suite because she was an FBI agent. The FBI again investigated Gloria for impersonation, but did not take action. 

By 1956 Gloria realized she needed a change of pace and moved to Chicago. She found a job as a layout artist at Advertising Promotions, Inc. and met artist Charles Russell Scimo. They married on November 26, 1958, and had a son on November 8, 1959.  

Gloria was soon in trouble with the law once more. She claimed her brother visited in 1958 and asked her to embezzle funds from her company. In other records, she claimed her brother was solely responsible for stealing the money. Regardless, between fifteen thousand and thirty thousand dollars were embezzled. Duplicate checks were made out for company bills and cashed into Gloria’s bank account. She was charged with embezzlement and forgery in May 1960 and jailed for over eighteen months.

Gloria adopted a new name upon her release from prison: Galya Zakharovna. Galya claimed the name came from a ballet dancer. Her attorney, John Kokish, speculated her inspiration was her parents’ hometown of Galva, Illinois. Whatever the source, it made her sound Russian. 

Now known as Galya, her FBI files indicate she may have continued as an FBI informant. Chicago, the original home of the Communist Party of the United States, teemed with Communist activity throughout the Cold War. Galya’s FBI dossier shows she had regular contacts with book publishers from Russia. Around 1964 she went to work for Tanenbaum Associates, an art company, where she dated Leo Tanenbaum, a Communist Party USA member.

A fellow informant reported Galya to the FBI in 1965: “Zakharovna was constantly talking and bragging about herself. She claimed that she had been a spy for the Russians during World War II and had been dropped behind the German lines for espionage purposes…she said that she had been the one responsible for designing the small radio transmitter which was concealed in an artificial olive.” Galya had been a young teenager living in Illinois during WWII so her tale was demonstrably untrue, and the report concluded, “Zakharovna definitely had an emotional or mental problem.” 

Galya and Leo had a daughter in February 1966. Galya listed her birthplace as Russia on the birth certificate. Galya divorced her second husband Scimo that April, but Leo’s family dissuaded him from marrying Galya. A judge ruled Galya could not use Leo’s last name since they weren’t married. In defiance, she added an extra “n” and became, for the first time, Galya Tannenbaum. In her journals, Galya claims to have met Thomas Riha around this time in Chicago and that they made plans to marry by summer 1967. However, Thomas applied for and received a professorship at the University of Colorado Boulder that August. 

Cold War, Cold Marriage

Colorado played a significant role in the Cold War. The North American Aerospace Defense Command (NORAD) was hewn out of Cheyenne Mountain in Colorado Springs to serve as an aerospace monitoring facility. The Air Force Academy trained the next generation of pilots. Peterson Air Force Base, Fort Carson, Lowry Air Force Base, and Buckley Air Force Base all played crucial roles in national defense. Rocky Flats and the Rocky Mountain Arsenal built parts for nuclear and chemical weapons. Missile silos dotted northern Colorado. Across the state and the nation, residents pondered the possibility of nuclear war. Students practiced duck-and-cover drills at school, and bomb shelters were constructed in even the most staid suburbs, including Thomas Riha’s own Boulder backyard.

Given the state’s strategic significance, the FBI and CIA were highly active in Colorado. CU Boulder students took an anti-CIA stance, and students forced a CIA recruiter off campus in November 1967. Riha’s Czech and Soviet connections caused the Denver CIA to include him in an investigation of US citizens who visited Czechoslovakia. “The CU History Department is a rather touchy group,” the Denver CIA field chief wrote in an April 1969 memo, referring to an attempt to contact Riha in 1968. “Since we could get no sure indication from his colleagues that [Riha] would be receptive to a CIA approach we finally let the matter drop.”

Galya Tannenbaum claimed she had moved to Boulder with Riha in the fall of 1967, and records show she loaned him seven thousand dollars to buy his home there. But none of his Boulder friends or colleagues ever saw her, and Thomas never mentioned her. Thomas—working on a new book about Russian politician Paul Miliukov—soon found Galya’s children too disruptive to his creative process. Galya claims they broke off the relationship because of this, and she moved back to Chicago in December 1967.

Galya returned to Colorado by March 1968. She arrived in Denver as a new person: “Colonel” Galya Tannenbaum, a retired military official with powerful connections. “I literally became the Colonel—felt like it, acted like it, and in fact became such a person…” wrote Galya. “For most of my life I have felt less than nothing...but as the retired Colonel I was somebody good, and I thought that there was nothing that I could do that would go wrong.…” 

Galya was surprised by sudden news about Thomas Riha in October 1968. With an established life in Boulder, an extensive European art collection, and popularity as a professor, Thomas had decided it was time to marry—and not to Galya. He dated several Boulder women before deciding he wanted a wife from Czechoslovakia. His third visit to Russia, leading a tour for university professors in summer 1968, seemed the perfect opportunity to find one. He asked his uncle to place an advertisement in Czech newspapers. Hundreds of women responded.

Unfortunately for Thomas, the USSR invaded Czechoslovakia in August 1968, making it too dangerous for him to visit. But his uncle knew of a Czech woman named Hana Hruska, a business student, living in New York City. Thomas visited Hana in August after returning from Russia. Despite a fifteen-year age gap (Thomas was thirty-nine; Hana was twenty-four), the pair announced their engagement weeks after meeting. Hana moved to Boulder, and the two married on October 13, 1968. 

Galya shocked wedding guests by interrupting the reception to speak with Thomas. Thomas informed the guests Galya was a retired colonel who was going to help bring his nephew Zdenek Cerveny to the United States. Zdenek was trying to escape Czechoslovakia after the USSR’s invasion, and Galya told Riha she could help. When Zdenek arrived in the US the following month, Thomas believed Galya had used her military connections to fast-track his immigration. In actuality, she had filed his application normally—the US government was expediting applications from Czech citizens due to the USSR’s invasion. 

Thomas and Hana’s marriage was not a happy one, especially after Hana enrolled in beauty school and made friends. Frugal Thomas had been expecting a housewife who maintained an impeccable household without spending any money. He forbade her from using salt or making long-distance telephone calls to her family in order to avoid bills. By February 10, 1969, Thomas filed for divorce. He became concerned when Hana hired a lawyer to receive money in the divorce. He thought “the Colonel” could help him again.

Galya told Thomas she could get Hana deported. One terrifying night in early March 1969, Galya forced Hana into a vehicle and drove her around Boulder and Denver for hours, trying to force her to sign paperwork and take an unexplained pill. Her efforts to get Hana to sign the mysterious paperwork were unsuccessful. But that same month, Galya wrote to the Denver Art Museum to donate Riha’s beloved European art collection, and she received two thousand five hundred and thirty-five dollars from Riha’s savings account.

Hana returned home on March 9, 1969, and ran to her bedroom. Shortly afterwards, Thomas and Galya began pounding on her door, demanding she sign paperwork. Hana refused and Galya threatened to shoot a gun through the door. Soon, an odd, sweet smell began to waft through the air. It was ether. Hana, coughing, threw open a window and screamed.

Riha’s neighbors heard Hana, dragged her out of the window, and brought her into their home. Hana smelled so strongly of ether they had to open their own windows. Galya called the Boulder police. When they arrived, she showed them an ether bottle hidden in Hana’s sheets and told them Hana was in the US illegally and was about to be deported. Galya claimed connections to federal immigration authorities, but when the police demanded to see identification, she provided only an expired Illinois driver license. The police decided it was a domestic disturbance and left. Hana fled to the Hotel Boulderado, where she stayed before returning to her family in New York. Her immigration documents were valid. She had never been in danger of deportation.

Thomas invited his nephew Zdenek to Galya’s house four days later. When he arrived, Thomas seemed happy. The next night, Friday, March 14, Thomas attended a party thrown by one of his teaching assistants, Jan Sorensen. At the party, Jan recalled he seemed nervous and frightened. He told her someone had followed him. Jan offered to let Thomas spend the night at her house. He declined, left, and climbed into his Volkswagen. After he drove off, he would never be credibly seen again. The professor had vanished.

Investigations and Information

The next morning, Saturday, March 15, Thomas missed a history symposium in Denver. His neighbor saw Galya let herself into Thomas’s house with a key and observed her children playing in Thomas’s yard. Friends peering into his windows saw his table had been set for breakfast, as Riha habitually did the night before. Police found his suitcases and clothing in place with tax documents strewn about his desk. This was unusual for the well-organized Thomas. His calendar noted a meeting with “the Colonel” scheduled for the week after his disappearance. 

On Wednesday, March 19, Riha’s divorce lawyer Richard Hopkins received a telegram signed “Thomas Riha.” It requested Hopkins “subdue the panic” over his disappearance and was followed by letters signed by Riha about the sale of his home. At least one of the letters was postmarked from Canada. Hana claimed the signatures on the letters did not appear authentic. By Thursday, Galya contacted Wheeler Realty to sell Thomas’s house. They also received letters signed by “Thomas Riha” authorizing the sale. 

Thomas’s friends and colleagues were worried. They searched for him across Boulder, even checking his bomb shelter. CU President Joseph Smiley contacted a wartime connection in the CIA for information. That CIA office reached out to the Denver CIA office and lead agent Michael Todorovich. A declassified memo from April 8, 1969, reveals the Denver CIA called the FBI, which said Riha was in a “safe haven known only to his attorney and that they were not concerned over his disappearance.” The Boulder CIA relayed this to Smiley, telling him Riha was “alive and well.” It is unknown where the FBI received this information, but it likely came either from Galya Tannenbaum or from Riha’s lawyer. After sharing this with Smiley, the Denver and Boulder FBI and CIA offices remained silent throughout 1969. 

Galya sold Thomas Riha’s car, telling the purchaser she was Mrs. Riha, and received a tax writeoff for donating Thomas’s art collection to the Denver Art Museum. She donated over 1000 books from Thomas’s home to Loretto Heights College in Denver. Galya maintained Thomas called her from places unknown and once even visited her in Denver. On July 30, Galya chartered a plane to fly Zdenek Cerveny to Texas. The check she used to pay the pilot, taken from Riha’s checkbook and featuring a “presigned” signature from Thomas, bounced. On August 11, Galya received a royalty check from Riha’s book sales for twenty-one hundred dollars. 

A trail of suspicious deaths followed Galya over the summer. She joined a metaphysical church called the Brotherhood of the White Temple where she met recent divorcee Barbara Egbert. Barbara introduced her to Gustav “Gus” Ingwersen, a seventy-eight-year-old inventor. He conducted experiments and had a vat of acid large enough to dissolve a body. Gus and Galya became close, and she wrote that she considered him part of her family. On June 15, 1969, three months to the day from Thomas’s disappearance, Galya brought Gus some freshly baked bread. 

On June 18 of that year, Galya called Gus’s family and sent them to check on him. His son arrived to find Gus dead. Police found Galya’s bread, white crystals, and a vial of cyanide on the table. Gus’s autopsy revealed he had died of cyanide poisoning. The bread was tested and did not contain cyanide. Gus had changed his will days before his death and left Gayla and her children stock shares. Everyone in Gus’s family knew the stock was worthless. The will was signed by Zdenek Cerveny and Esther Foote, a Colorado Spring teacher who was tutoring Galya’s children. A small boy around the age of Galya’s son had delivered the will to a courthouse on June 19. It contained several odd spelling errors like “famlies,” “visable,” and “lonliness.” Gus was not known for spelling errors. His family was confused—they had never heard of Galya Tannenbaum. A handwriting expert hired by Gus’s children determined Gus’s will was a forgery. Oddly, Thomas Riha’s engraved wedding ring was discovered in Gus’s home. Galya claimed she had given it to Gus so he could remove the engraving from it. 

Galya continued to attend church with Barbara Egbert, the recent divorcee. On September 10, Barbara wrote to her parents that she was seeing Galya for dinner. On September 12, Galya called Barbara’s family and asked them to check on her. Barbara’s ex-husband found Barbara lying on her living room floor, dead. A typewritten will and note riddled with spelling errors lay nearby. Barbara was usually an excellent speller. An autopsy found she had died from cyanide poisoning. Barbara left Galya one of her artworks, but otherwise Galya did not financially benefit from Barbara’s death.

Galya dropped the Colonel persona sometime during the late summer or fall of 1969. She wrote, “Everything that happened with Tom was like it happened in a dream—and I’d wake up and all would be as it was.” Police began to suspect Galya of murder because Esther Foote, the Colorado Springs tutor whose signature was on Gus’s will, insisted she hadn’t signed it. Zdenek Cerveny claimed Galya forced him to sign the will. With this evidence, police arrested Galya for forgery on October 27, 1969. Police found cyanide and Thomas Riha’s passport in her home. While out on bond, Galya was arrested again for burglarizing a Golden house on December 31 and attempting to cash stolen checks. Young attorney John Kokish took Galya’s case, thinking it would be simple. He was wrong.

Denver Post reporter Fred Gillies had also been investigating the Riha disappearance. His December 28, 1969, article was the first real press on Riha since early 1969. Gillies’s story prompted an important tip: an auto shop reported they had fixed Galya’s car, covered in red mud with a damaged front, in late March. She told the mechanics she had been chasing a soldier in the mountains. Galya owned several lots in the mountains in an area with red dirt—remote lots where a body could be easily hidden.

Gillies’s article also prompted Denver District Attorney James “Mike” McKevitt to investigate Riha’s disappearance. He asked CU Boulder president Joseph Smiley where he’d learned Riha was “alive and well.” Smiley, scared, contacted the Denver CIA. The Denver CIA convinced McKevitt to stop his investigation, and Smiley issued a statement saying the “alive and well” statement had been a misunderstanding. Meanwhile, Colorado Representative Donald Brotzman requested information from the US Attorney General. The AG forwarded Brotzman’s letter to FBI director J. Edgar Hoover, who responded, “We have no knowledge concerning Dr. Riha’s whereabouts.”

Declassified memos reveal Hoover was angry about a potential breach of internal security. Hoover had ruled the FBI since June 1935, controlling flows of information and committing abuses of power that would come to light only after his death in 1972. He demanded to know which FBI agent had told the CIA that Riha was “alive and well.” Colorado CIA and FBI offices remained silent, knowing the agent responsible would be terminated. Livid, Hoover wrote a memo to the Denver FBI office: “IMMEDIATELY DISCONTINUE ALL CONTACT WITH THE LOCAL CIA OFFICE.” He sent out national orders for all FBI offices to cease contact with the CIA. He then cut off communication with all agencies except the White House to avoid the appearance of bias. Unable to control information, Hoover simply stopped it.

“I Didn’t Kill Riha”

Galya Tannenbaum, imprisoned in a psychiatric hospital in early 1970, began journaling her life story. She insisted she was not responsible for Thomas’s disappearance and pinned blame on intelligence agencies or Riha’s ex-wife Hana. But local police continued to suspect her, zeroing in on the letters allegedly signed by Thomas after his disappearance. The letters featured spelling errors commonly made by Galya but not by Thomas. Gus Ingwerson’s will and Barbara Egbert’s final letter contained similar errors. Meanwhile, the Denver FBI quietly conducted and closed an impersonation case on Galya Tannenbaum. “The claim by TANNENBAUM of Bureau employment is absolutely untrue,” the Denver field chief wrote to J. Edgar Hoover in July 1970. Declassified records reveal the FBI had gathered information on Riha during its investigation into Tannenbaum, making their claim that they knew nothing about him untrue.

Galya’s forgery trial began July 8, 1970. Psychiatric experts argued over Galya’s mental state during 1969. Notaries testified Galya had passed herself off as “T. Riha” or “Mrs. Riha” in order to get signatures notarized. A handwriting expert testified Riha had not written any signatures after he disappeared, but could not determine whether Galya had written them. The judge declared Galya had been unable to determine between right and wrong when she forged Riha’s checks and committed her to the state mental hospital in Pueblo.

At the hospital, Dr. David Olenik restricted Galya’s activities so she wouldn’t manipulate staff. Galya convinced a technician named Henry Madrid she had powerful connections outside the hospital and he would be held responsible if she died. While in Denver for a trial over forging documents for Riha’s Volkswagen sale, she told people she had hidden cyanide at the hospital. After she returned to Pueblo, Galya gave Henry a package and instructed him to hide it. He stashed it in his garage.

Galya was struggling in the hospital—she lost a job typing papers on March 4, and she faced additional legal action in April. On March 6, Galya met Henry in a common room around 9:30 p.m. Galya went to the restroom. Afterward, she asked for his hand. “I took it,” she said. Henry would testify that she said “I didn’t kill Riha.” News reports would claim she said, “He made it to Russia.” She then fell unconscious. Henry suspected cyanide but did not mention it, and retrieved nurses who noticed the smell of almonds in the air. Galya was treated for unknown poisoning and died at 12:40 a.m. on Sunday, March 7, 1971. 

Galya’s attorney John Kokish received her letters the next morning. She had sent him the letters knowing hospital staff would not open them due to attorney-client privilege and mailed them on Friday so he would not receive them in time to stop her. Galya’s letters blamed Dr. Olenik for her death. The Colorado Bureau of Investigation launched an inquiry. Her autopsy revealed she had consumed cyanide, but the inquiry could not uncover how Galya had smuggled it into the hospital. When Henry gave Galya’s packet to police, testing showed it contained enough cyanide to kill a dozen people. “She really got all of us,” Dr. Olenik would later write. “…There was always a very angry element that we could never do enough for her.”

The mystery surrounding Thomas Riha’s disappearance did not die with Galya. After 1973’s Watergate scandal, Idaho Senator Frank Church chaired a committee in 1975 to investigate whether the CIA and FBI had been committing illegal spying activities. Colorado Senator Gary Hart included Thomas Riha’s disappearance in this investigation. Senators were concerned Hoover’s 1970 order to stop communication between the FBI and CIA had impaired the effectiveness of US intelligence operations. The committee concluded Riha’s disappearance was responsible for the communication rift and decided Riha was likely alive based on a previously classified report claiming someone had sighted Thomas in Prague. However, the informant claimed to know Riha from a school they both attended in Bratislava. Thomas Riha never attended school in Bratislava, casting the claim in doubt. 
 

A Colorado Cold Case

Thomas’s family was left to pick up the pieces. His mother Ruth died in February 1970 never knowing what happened to her only child. Her written pleas to the FBI had yielded no information. Thomas’s nephew Zdenek petitioned the Denver Probate Court to declare him dead. In 1979, Thomas’s estate was divided up and disbursed. Hana Riha received five thousand dollars of Thomas’s fourteen-thousand-five-hundred-dollar-estate. Riha’s increasingly desperate attempts to keep Hana from receiving money in the divorce had been in vain.

Author Rachel Mann researched the Riha case in the 1990s. Galya’s lawyer John Kokish shared Galya’s journals and his casefiles with Mann. In February 2015, Kokish and Mann donated their materials and research to History Colorado.

Thomas Riha’s disappearance has never been solved. Russian and Czech embassies denied having any information about him. The FBI and CIA, both locally and nationally, continue to maintain they know nothing about Riha’s disappearance and never investigated it outside of Hoover’s attempts to find the FBI agent who told the CIA Riha was “alive and well.” But against the tense backdrop of Cold-War Colorado, Riha’s friends and family had no difficulty suspecting espionage played a role. What happened to Thomas Riha when he left the party shortly after midnight on March 15, 1969? Was he removed by an intelligence agency? Did he flee a marriage gone wrong? Did Galya Tannenbaum have something to do with it? She financially benefited from his disappearance, but only forgery was ever proven in court. The case remains cold. Someone knew what happened to Thomas Riha. The question is: who?

View The Disappearance of Thomas Riha exhibition at the History Colorado Center through March 15, 2026.