By . Rachel Quigley . PUBLISHED: . 15:29 EST, 15 August 2013 . | . UPDATED: . 15:40 EST, 15 August 2013 . The father of missing Utah woman Susan Powell - who has been missing since 2009 - is determined to keep looking for his daughter even though police have given up, and still has hope she may be alive, it emerged today. Chuck Cox, from Oregon, has now dedicated his life to finding his daughter and spends most of his days traveling along Interstate 84 - where he believes Josh Powell may have disposed of her body - and following up tips. He retired from his job as a veteran crash investigator with the Federal Aviation Administration so he could spend his days searching. His experience tells him his daughter - who was just 28-years-old when she disappeared - is dead, but the father in him dearly wants to believe she is alive. Grieving: Mrs Powell's parents Chuck and Judy Cox outside their home after their grandsons' death. Chuck said he will not stop searching for his daughter . Missing: Susan Powell vanished from the couple's Utah home in 2009. She had said she feared her husband . Remembrance: Chuck and Judy Cox, left, are joined by Susan's sister Denise Cox, right, and her fiancé, Andrew Olsen, at Woodbine Cemetery in Puyallup, where Susan's sons Charlie and Braden Powell are buried . Susan Powell was last seen at her home on December 6, 2009. Her husband Josh took their two sons on an impromptu camping trip even though it was mid winter and freezing temperatures. He was later named a person of interest but was never arrested in the case. Cox strongly believed he was responsible for the disappearance of Susan and begged police to arrest Josh. But they never did, and three years later during a supervised visit with his sons, Josh took an axe to them and killed them before setting his Washington home on fire, killing all three of them. His brother has since committed suicide and his father is currently serving time in jail for voyeurism. Cox believes that all three of them had a hand in Susan's disappearance. Due to the stress of the ordeal, Cox has lost 60 pounds. It has also taken its toll on his relationship with his wife and remaining daughters who want him to give up. 'If it were up to me, I'd pack up and be gone. I'd buy a camper and stay on the road until I found her,' he told the LA Times. 'I tell my daughters I love them, but that I'm going to find Susan. I'm not going to give up on her. I can't.' One of his daughters Denise Olsen, 34, sometimes helps her dad on his searches and explains how - even four years later - her sister's disappearance still has a heavy effect on him. Piling on the pressure: In newly-released tapes, Josh Powell evaded questions from the police the day after his wife Susan disappeared in 2009 . Family tragedy: Susan Cox Powell, pictured with her sons Charlie and Braden, disappeared in 2009. Her husband Josh killed himself and their sons in 2012 . 'After losing Susan, he's been a lot . more open and understanding,' she said. 'But every time he talks of not . stopping until he finds her, his eyes tear up. And you just have to . change the subject.' Cox is getting no help from police - they stopped their search for Susan in . May announcing they had run out of leads and had no choice but to wait . for new information. This frustrates him greatly as he believes they are holding on to vital evidence which could help him finally find his daughter. Cox is considering suing West Valley City police because they refuse to . release case files and have treated him like he is a 'meddling parent . rather than a veteran investigator', he said. 'I was the victim's father, a parent. The idea was, "We can't trust him. He's a civilian, not . capable of grasping the intricacies of police work". In reality, I was a . veteran investigator. 'But I wasn't a cop. I didn't carry a gun. I . understood why they didn't include me. They had to do the investigation. But their look always said, "You're not one of us".' Devoted: Cox is not ready to give up. He has had no satisfaction of a conviction for either his daughter or grandsons and has not had the closure of a funeral. So he continues to spend his days searching and hoping . Explosion: Josh Powell set his home on fire, killing himself and his two sons in 2012 . Mike Powell - no relation - a deputy police chief in West Valley City, explained their decision to distance him to the LA Times. 'Just because he was an FAA investigator . doesn't make him part of this investigation. It wasn't . prudent to tell him everything that was going on,' he said. 'There are aspects to this case that are not for public consumption. We have to respect the privacy of certain individuals.' Cox . has turned his home in Puyallup into his headquarters where he looks . through case files, works on tips from the public and writes his blog. He is considering getting a cadaver dog to help him in his search. His blogs also encourage women with abusive husbands to get help. And as he searches, he still speaks of Susan like she is alive. 'She's a very happy person, the kind . who'd find a roomful of manure and say all this means is there's got to . be a pony in here somewhere,' he said, using the present tense. Cox . is not ready to give up. He has had no satisfaction of a conviction for . either his daughter or grandsons and has not had the closure of a . funeral. So he continues to spend his days searching and hoping. The Weekend of December 6 and 7, 2009 . - Susan Powell, then 28, is last seen at the West Valley City, Utah, . home she shares with her husband Josh and their two sons. Josh Powell . tells police that he decided to take his boys on an impromptu camping . trip that night in the middle of a blizzard but returns home to find his . wife gone.December 24, 2009 . - After two weeks of investigations during which Braden and Charlie . confirm the camping trip, Josh Powell is named a person of interest in . his wife's disappearance. Josh's . father, Steven, tells the media he thinks Susan skipped town with a man . from St. George, Utah, who also vanished from a party the same night . she was last seen. January 2010 . - Josh Powell decides to move with his two sons to Puyallup, . Washington, which is where he and Susan grew up. He has now begun to . tell the media his wife was 'extremely unstable' and was mentally ill. August 18, 2011 . - Investigators working on a lead travel to abandoned mine shafts in . Ely, Nevada, 200 miles away from West Valley. However, nothing is found.August 20, 2011 . - At a remembrance service for Susan, Steven Powell and her father . Chuck Cox engage in a public shouting match in which Powell calls Cox a . 'liar'.August 25, 2011 . - Forensic investigators remove three computers from Josh Powell's home . and Steven Powell claims that Susan made sexual advances on him that . were 'a little beyond the pale'.September 14, 2011 . - Authorities in Utah find a shallow grave in a mountainous region . which they believe could contain the remains of Susan Powell - the site, . near to Topaz Mountain is 30 miles from where Josh said he took the . boys camping. September 22, 2011 . - Steven Powell is charged with child pornography charges after the . computers removed from his sons house reveal incriminating evidence. September 23, 2011 . - Steven Powell and Josh Powell are issued with an injunction . preventing them from publishing any material from Susan Powell's . journals. September  28, 2011 . - Josh Powell's sons are removed from his custody and placed with Chuck . and Judy Cox because they are living in a home with sexually explicit . material. He is, however, granted visitation rights with his boys. February 1, 2011 . - Josh Powell is ordered to take a psychosexual evaluation and . polygraph test to regain custody of his boys. Police note that there is . information and images on his computer that 'specifically related to . their children's welfare.' February 5, 2012 - Josh Powell sets off an explosion at his Washington home today that killed himself and his two sons. May 2012 - Steven Powell began a prison sentence for 14 counts of voyeurism. February 11, 2013 . - Michael Powell files motion attempting to have his brother's $1.5 . million life insurance policy which he was a beneficiary of paid out. May 20 - Police announce their investigation into Susan's disappearance is closed and release the documents.
Susan Cox Powell vanished from the family home in Salt Lake City in the middle of the night in 2009 .
Charlie Cox has always suspected her husband Josh was responsible .
Josh Powell set fire to his home, killing himself and his two sons in 2012 .
Cox retired from his job to spend the rest of his days looking for Susan .
By . Rachel Quigley . PUBLISHED: . 15:29 EST, 15 August 2013 . | . UPDATED: . 15:40 EST, 15 August 2013 . The father of missing Utah woman Susan Powell - who has been missing since 2009 - is determined to keep looking for his daughter even though police have given up, and still has hope she may be alive, it emerged today. Chuck Cox, from Oregon, has now dedicated his life to finding his daughter and spends most of his days traveling along Interstate 84 - where he believes Josh Powell may have disposed of her body - and following up tips. He retired from his job as a veteran crash investigator with the Federal Aviation Administration so he could spend his days searching. His experience tells him his daughter - who was just 28-years-old when she disappeared - is dead, but the father in him dearly wants to believe she is alive. Grieving: Mrs Powell's parents Chuck and Judy Cox outside their home after their grandsons' death. Chuck said he will not stop searching for his daughter . Missing: Susan Powell vanished from the couple's Utah home in 2009. She had said she feared her husband . Remembrance: Chuck and Judy Cox, left, are joined by Susan's sister Denise Cox, right, and her fiancé, Andrew Olsen, at Woodbine Cemetery in Puyallup, where Susan's sons Charlie and Braden Powell are buried . Susan Powell was last seen at her home on December 6, 2009. Her husband Josh took their two sons on an impromptu camping trip even though it was mid winter and freezing temperatures. He was later named a person of interest but was never arrested in the case. Cox strongly believed he was responsible for the disappearance of Susan and begged police to arrest Josh. But they never did, and three years later during a supervised visit with his sons, Josh took an axe to them and killed them before setting his Washington home on fire, killing all three of them. His brother has since committed suicide and his father is currently serving time in jail for voyeurism. Cox believes that all three of them had a hand in Susan's disappearance. Due to the stress of the ordeal, Cox has lost 60 pounds. It has also taken its toll on his relationship with his wife and remaining daughters who want him to give up. 'If it were up to me, I'd pack up and be gone. I'd buy a camper and stay on the road until I found her,' he told the LA Times. 'I tell my daughters I love them, but that I'm going to find Susan. I'm not going to give up on her. I can't.' One of his daughters Denise Olsen, 34, sometimes helps her dad on his searches and explains how - even four years later - her sister's disappearance still has a heavy effect on him. Piling on the pressure: In newly-released tapes, Josh Powell evaded questions from the police the day after his wife Susan disappeared in 2009 . Family tragedy: Susan Cox Powell, pictured with her sons Charlie and Braden, disappeared in 2009. Her husband Josh killed himself and their sons in 2012 . 'After losing Susan, he's been a lot . more open and understanding,' she said. 'But every time he talks of not . stopping until he finds her, his eyes tear up. And you just have to . change the subject.' Cox is getting no help from police - they stopped their search for Susan in . May announcing they had run out of leads and had no choice but to wait . for new information. This frustrates him greatly as he believes they are holding on to vital evidence which could help him finally find his daughter. Cox is considering suing West Valley City police because they refuse to . release case files and have treated him like he is a 'meddling parent . rather than a veteran investigator', he said. 'I was the victim's father, a parent. The idea was, "We can't trust him. He's a civilian, not . capable of grasping the intricacies of police work". In reality, I was a . veteran investigator. 'But I wasn't a cop. I didn't carry a gun. I . understood why they didn't include me. They had to do the investigation. But their look always said, "You're not one of us".' Devoted: Cox is not ready to give up. He has had no satisfaction of a conviction for either his daughter or grandsons and has not had the closure of a funeral. So he continues to spend his days searching and hoping . Explosion: Josh Powell set his home on fire, killing himself and his two sons in 2012 . Mike Powell - no relation - a deputy police chief in West Valley City, explained their decision to distance him to the LA Times. 'Just because he was an FAA investigator . doesn't make him part of this investigation. It wasn't . prudent to tell him everything that was going on,' he said. 'There are aspects to this case that are not for public consumption. We have to respect the privacy of certain individuals.' Cox . has turned his home in Puyallup into his headquarters where he looks . through case files, works on tips from the public and writes his blog. He is considering getting a cadaver dog to help him in his search. His blogs also encourage women with abusive husbands to get help. And as he searches, he still speaks of Susan like she is alive. 'She's a very happy person, the kind . who'd find a roomful of manure and say all this means is there's got to . be a pony in here somewhere,' he said, using the present tense. Cox . is not ready to give up. He has had no satisfaction of a conviction for . either his daughter or grandsons and has not had the closure of a . funeral. So he continues to spend his days searching and hoping. The Weekend of December 6 and 7, 2009 . - Susan Powell, then 28, is last seen at the West Valley City, Utah, . home she shares with her husband Josh and their two sons. Josh Powell . tells police that he decided to take his boys on an impromptu camping . trip that night in the middle of a blizzard but returns home to find his . wife gone.December 24, 2009 . - After two weeks of investigations during which Braden and Charlie . confirm the camping trip, Josh Powell is named a person of interest in . his wife's disappearance. Josh's . father, Steven, tells the media he thinks Susan skipped town with a man . from St. George, Utah, who also vanished from a party the same night . she was last seen. January 2010 . - Josh Powell decides to move with his two sons to Puyallup, . Washington, which is where he and Susan grew up. He has now begun to . tell the media his wife was 'extremely unstable' and was mentally ill. August 18, 2011 . - Investigators working on a lead travel to abandoned mine shafts in . Ely, Nevada, 200 miles away from West Valley. However, nothing is found.August 20, 2011 . - At a remembrance service for Susan, Steven Powell and her father . Chuck Cox engage in a public shouting match in which Powell calls Cox a . 'liar'.August 25, 2011 . - Forensic investigators remove three computers from Josh Powell's home . and Steven Powell claims that Susan made sexual advances on him that . were 'a little beyond the pale'.September 14, 2011 . - Authorities in Utah find a shallow grave in a mountainous region . which they believe could contain the remains of Susan Powell - the site, . near to Topaz Mountain is 30 miles from where Josh said he took the . boys camping. September 22, 2011 . - Steven Powell is charged with child pornography charges after the . computers removed from his sons house reveal incriminating evidence. September 23, 2011 . - Steven Powell and Josh Powell are issued with an injunction . preventing them from publishing any material from Susan Powell's . journals. September  28, 2011 . - Josh Powell's sons are removed from his custody and placed with Chuck . and Judy Cox because they are living in a home with sexually explicit . material. He is, however, granted visitation rights with his boys. February 1, 2011 . - Josh Powell is ordered to take a psychosexual evaluation and . polygraph test to regain custody of his boys. Police note that there is . information and images on his computer that 'specifically related to . their children's welfare.' February 5, 2012 - Josh Powell sets off an explosion at his Washington home today that killed himself and his two sons. May 2012 - Steven Powell began a prison sentence for 14 counts of voyeurism. February 11, 2013 . - Michael Powell files motion attempting to have his brother's $1.5 . million life insurance policy which he was a beneficiary of paid out. May 20 - Police announce their investigation into Susan's disappearance is closed and release the documents.
following up tips. He retired from his job as a . Missing: Susan Powell vanished from the responsible for the disappearance of Susan and tragedy: Susan Cox Powell, pictured with her sons Charlie and Braden, disappeared in 2009. Her continues to spend his days searching and hoping . Explosion: Josh Powell set his home on fire, killing himself and his two sons in 2012 . Mike impromptu camping . trip that night in the middle