SNYDER -- Remains found near a remote West Texas lake last month are those of a 13-year-old middle school cheerleader missing since December 2010, authorities announced Friday.The body was found near Lake J.B. Thomas in Scurry County on March 16, more than two years after Hailey Darlene Dunn's mother reported her daughter missing.The girl's disappearance and the cause of her death remain under investigation, Scurry County Sheriff Trey Wilson said at a news conference Friday.The Scurry County district attorney's office received written confirmation of the identity of the remains on Friday, he said.A person who has not been identified called authorities to report finding the body about 20 miles from the girl's hometown of Colorado City.The girl had been the subject of months of intensive searches in and around Colorado City and surrounding fields and landfills after her mother, Billie Jean Dunn, reported her missing on Dec. 28, 2010. More than 100 billboards featuring her picture and information about the case went up along interstates in Texas and other states.Shawn Adkins, who was Billie Jean Dunn's boyfriend when Hailey went missing, has said the girl told him on Dec. 27, 2010, that she was going to her father's home nearby and then on to spend the night at a friend's home. She did neither.Authorities called Adkins as a "person of interest" in the girl's disappearance, but he has not been charged. Authorities later accused the girl's mother of lying about the whereabouts of Adkins, who was found at her home. Billie Dunn pleaded no contest in June 2011 to making a false report to law enforcement and received a suspended 90-day jail term with probation.The mother and Adkins have denied involvement in Hailey's disappearance. Billie Jean Dunn broke off her relationship with Adkins last year, Young said.Freda Radcliff, who led Hailey's Angels, an organization dedicated to finding the girl, attended Friday's news conference."We've been searching for her for two years, and it's like losing a child of your own. I hate it. I wish we could have brought her back," Radcliff said.Hailey's paternal grandmother, Connie Jones, said, "We can bury her. She can go home to her maker. She can be at peace."Hailey's paternal grandfather, Bill Dunn, died in 2011, six months after the girl went missing. His widow, Spicy Dunn of Ponca City, Okla., said her husband spent much of the last months of his life trying to learn what became of his granddaughter."He was very, very hurt, and was on the computer all the time looking and trying to find anything that had to do with Hailey," she said Friday. "Anything."She said family members made a point not to change phone numbers so that law enforcement officials could reach them.