GOLDSBY, Oklahoma - Authorities confirm the human remains located in McClain County Thursday afternoon are those of missing Piedmont teenager Anne Hill.

The teen disappeared a year ago this month. She told her mother she was going to a friend's house and was never seen again. Anne Hill, 16, of Piedmont vanished in April 2014. Authorities initially assumed she was a runaway until her car turned up one week later abandoned at Fink park in Edmond. Since then, police and private investigators have been canvasing hundreds of miles in the search for her body.

The McClain County Sheriff's office began investigating after a skull was found in a rural area just south of Goldsby, Okla., just before noon Thursday. The sheriff's office confirmed with News 9 that the skull was found near State Highway 74 and W. Ladd Rd

Thursday night there was a break in the case.

“The seismograph crew was gridding this area, and they came across a gruesome discovery,” McClain County Sheriff Don Hewett said. “They came across a skull just out in the pasture.”

There are 320 acres locked down as a crime scene, with so far only one piece of evidence.

“We think it's a larger head than a child,” Hewett said.

The OSBI Forensic team as well as the medical examiner crossed the cattle guard to the property and somehow at some unknown time someone else did, too.

Several months ago, investigators were searching very near this area for the remains of Anne Hill, and about 9 p.m. Thursday they confirmed it is her.

“We will be gridding this area and will probably be out here a couple of days and see if we can uncover any more evidence,” Hewett said.

There are two suspects in her death. Chadd Raymond is serving a life sentence after pleading guilty to his role, and Chloe Thomas is in jail on a first degree murder charge.

She's expected to be in court Friday morning for a preliminary hearing.

Keep checking with News 9 and News9.com for more information.