The 18-year-old Florida girl 'infatuated' with the Columbine massacre killed herself in a Colorado forest following a massive manhunt that saw schools across Denver shut down.

Sol Pais was found dead from a self-inflicted gunshot wound near the Echo Lake Campground in Mt Evans, just outside Denver, on Wednesday morning.

Witnesses told local media that Pais had earlier been spotted running naked through the woods with a gun.

Nearly 30 armed law enforcement officers swarmed the area in the moments before confirming that Pais was dead.

It is not yet clear when she took her own life but Jefferson County Sheriff Jeff Shrader said he didn't believe authorities were in active pursuit at the time her body was found.

Sol Pais, 18, was found dead from an apparent self-inflicted gunshot wound near the Echo Lake Campground in Mt Evans, just outside Denver, on Wednesday morning

The FBI revealed on Wednesday afternoon that Pais had last been spotted in that wooded area when she was dropped off by a driver on Monday afternoon.

The driver reported the information to authorities on Tuesday after investigators started their frantic search for Pais in the Denver area.

The teen had flown from Miami to Denver on Monday and bought a pump-action shotgun and ammunition just days before the 20th anniversary of the mass shooting at Columbine High School that killed 13 people.

A disturbing website belonging to Pais, as well as posts on the National Gun Forum seeking advice on buying a shotgun in Colorado, had emerged earlier on Wednesday as the manhunt was underway

Authorities said Pais had become 'infatuated' with the Columbine shooting and became concerned when she purchased three one-way tickets to Denver for Monday, Tuesday and Wednesday.

The FBI had described the Miami Beach High School senior as 'extremely dangerous' and said she had made threats to 'commit an act of violence' in Denver after becoming fixated on the shooting massacre.

Half a million students were forced to stay home on Wednesday as the manhunt for Pais continued.

They said she had not made a specific threat but said her fascination with the massacre and the gunmen and her recent actions had raised suspicions.

Two teenage boys who attended Columbine High School shot and killed 12 classmates on April 20, 1999 before committing suicide. At the time, it was the deadliest school shooting in U.S. history.

A disturbing website belonging to Pais, as well as posts on the National Gun Forum seeking advice on buying a shotgun in Colorado, emerged as the manhunt was underway.

The FBI said they are looking at the website and other online activity as part of their investigation.

The website is filled with self-hate journal entries and contains a tribute to a Marilyn Manson song that was inspired by the high school shooting.

DailyMail.com has viewed the website but has chosen not to publish copies of the diary entries.

Investigators head into the forest near the Echo Lake Campground in Mt Evans, just outside Denver, on Wednesday where the body of Pais was found

Nearly 30 armed law enforcement officers swarmed on the area near the Echo Lake Campground in the moments before confirming Pais was found dead. Investigators are pictured above after the girl's body was found

Sol Pais was found near the Echo Lake Campground in Mt Evans, just outside Denver, on Wednesday morning

The site contains photocopied handwritten journal entries with multiple drawings of guns and troubling phrases like 'being alive is f**king overrated' and 'how do I pull it out of me? I'm f**king empty.'

The website also has the phrase '1999 - the nobodies' written on it. Marylin Manson wrote a song titled The Nobodies based on the 1999 shooting massacre at Columbine.

Another social networking page found under Pais' name contains a profile photo bearing a resemblance to photos released by authorities during the manhunt for her.

It asked for readers to be the 'best killers'.

The profile, which also contains a link back to the website with the journal entries, also has five items listed on a to do list, including: 'Self destruct, burn out, walk away, reject apologies and fade.'

She was also believed to be behind a series of posts on the National Gun Forum website last month asking for advice on buying a gun in Colorado.

'Florida resident here. I am planning a trip to Colorado in the next month or so and wanna buy a shotgun while I'm there and I was wondering what restrictions apply for me? I've found a few private sellers I might want to purchase from; is it legal for me as a Florida resident to purchase a shotgun in Colorado? I'm 18 years old too, if it's important,' she wrote.

'The problem is i have no friends in FL who are into guns like me so it's not as fun having to do all of this alone,' she wrote in a follow up post.

The FBI searched the Miami Beach home where Pais lives with her parents on Tuesday night and remained outside on Wednesday

Police vehicles sit outside Columbine high school as some Denver area schools have closed while police searched for Pais

The Denver FBI office was alerted to the potential threat early Tuesday by Miami FBI agents and they notified area schools that afternoon.

About a dozen Denver area districts called off classes for Wednesday and about a half million students were forced to stay home because authorities believe Pais could pose a threat to a school.

Columbine and more than 20 other schools outside Denver locked their doors for nearly three hours on Tuesday afternoon before Wednesday's complete closures were announced.

An FBI bulletin from early Tuesday said authorities lacked probable cause for a formal arrest but that law enforcement should detain Pais for a mental-health evaluation.

Officials released two photos of Pais and said she was last seen in the foothills of Jefferson County on Monday dressed in a black T-shirt, camouflage pants and black boots.

The FBI searched the Miami Beach home where Pais lives with her parents on Tuesday night and remained outside on Wednesday.

At the time, the teenager's father Gardi Pais, 58, told DailyMail.com that the family had not heard from her since Sunday.

The elder Pais said he thought his daughter had a 'mental problem' and begged her to return home.

'They are looking for her. We don't have any idea,' he said from behind his Florida front door on Tuesday.

Asked if he had a message for his daughter, Pais said: 'Please come home.' His voice trembling, he added: 'I think she's gonna be okay. I think maybe she has got a mental problem.'

Classmates at Miami Beach High School told the Miami Herald that Pais was taking AP and honor roll classes.

'She didn't seem any type of way,' Justin Norris, 18, said. 'She was just bad at starting conversations.'

Eliana Donaire, 17, said: 'She was very quiet. I would usually see her doing homework... she didn't seem weird.'

Denver public schools were shut down as a precaution on Wednesday. Pictured is Columbine High School principal Scott Christy (right) and an law enforcement officer watching on as students left on Tuesday