JEFFERSON COUNTY, Colo. — After a massive manhunt along the Front Range and foothills west of Denver, Sol Pais was found dead by a self-inflicted gunshot wound Wednesday morning near the base of Mt. Evans, according to the FBI and Colorado law enforcement agencies.

The 18-year-old woman from Surfside, Fla. had been wanted by authorities since Tuesday morning after allegedly making "credible" threats toward schools in the Denver metro area. Pais was “infatuated” with the Columbine school shooting, authorities said. She was found dead around the base of Mt. Evans.

Two high-ranking sources told Denver7's Jace Larson that Pais took her own life with a self-inflicted gunshot wound. As far as the Clear Creek County Sheriff's Office could tell, she was by herself and was found around 9:54 a.m., the sheriff said. Tips from the FBI and community members led them to her body, which was found off trail.

She was brought to the Echo Lake Campground area by a ride-share driver, who relayed that information to authorities, according to FBI Special Agent in Charge Dean Phillips.

The FBI tweeted shortly afterward that there was no longer a threat to the community. Phillips said at an afternoon news conference that authorities believed Pais died of a self-inflicted gunshot wound but that a medical examiner would confirm if that was the case.

Jefferson County Sheriff Jeff Shrader said he didn't believe there was an active pursuit when she was found dead, though there were plenty of staff on the ground searching in different areas. He said everything they have learned so far does not indicate that she had any assistance — just a fascination with Columbine and the shooting 20 years ago.

Pais purchased three one-way tickets from Florida to Colorado for April 15, 16 and 17, Phillips said Wednesday. She flew into Denver on Monday, the 15th.

She took a ride-share service directly to a gun store in Jefferson County not far from Columbine High School and purchased a shotgun and ammunition, according to the FBI. Authorities said she legally purchased the shotgun. Phillips said that Pais had contacted more than one gun store before she left Florida.

READ MORE: Jefferson County gun shop owner: Sol Pais legally bought gun, passed background check

Josh Rayburn, owner of Colorado Gun Broker, told Denver7's Tony Kovaleski that he "did not sleep all night" after learning he had sold a gun, which cost about $300, to Pais on Monday. Her background check was clear, he said, and they had no reason to suspect she was a threat.

BREAKING Gun shop owner “I did not sleep all night” after learning he sold a pump shotgun to Sol Pais for $300. Pic of store and background check that came back in 20 mins @DenverChannel pic.twitter.com/K3hBDBKhrJ — Tony Kovaleski (@TonyKovaleski) April 17, 2019

"We didn't know she was a threat until after the weapon had been procured," Phillips said.

She was last seen in the foothills of Jefferson County on Monday, but authorities did not name her exact location. The FBI in Miami contacted the Denver office after she was reported missing by her parents, Shrader said.

Jefferson County Sheriff's Office placed several schools on lockout Tuesday afternoon after the sheriff's office identified what appeared to be a "credible threat," though the details of the threat were not clear or directed toward one school in particular. The sheriff's office said Pais was connected to the threat and was considered armed and dangerous.

The ABC affiliate in Miami reported that a man who said he was her father told news crews that he last saw his daughter Sunday and the situation has "been a nightmare" since then. Phillips said Wednesday afternoon that Pais' parents reported her missing Monday, and that the FBI's Miami field office was alerted to her possibly being a threat "based upon her actions and comments she made to others."

A missing person's reported obtained by Denver7's Jace Larson states Sylvia Pais last saw her daughter on Sunday evening. It goes on to state that the 18-year-old left for school at around 6:15 a.m. the next day and that her daughter would sometimes take an Uber if she missed her bus. At about 6:32 a.m., Sol texted her mother and told her she was going to go to an art history review after school, but the teenager did not say where the art history review would take place. Further, the missing person's report shows that after that last text, Sol stopped replying to texts or answering phone calls, which would go straight to voicemail. Her mother told police Sol "has never done this before and has never done any drugs," and that the 18-year-old had no friends and usually stayed at home.

After this information was relayed to authorities, the Miami office notified the Denver office, which then started working with the Jefferson County Sheriff's Office to place Columbine and other nearby schools on lockout.

About 150 schools and districts closed Wednesday as a precaution.

At a press conference Wednesday morning, Jefferson County Public Schools and the sheriff's office said they are focusing on getting students back into school Thursday and ensuring upcoming Columbine anniversary events are carried out in a safe manner. Schools on Thursday will run as normal, but will have extra security, said JeffCo Public Schools Superintendent Jason Glass. Staff had already started to work on a plan for Thursday if Pais wasn't located.

"We did not wish to have one person hold all of the schools in the Front Range, or the whole state, hostage," he said.

While they didn't have to use it, they have saved that procedure in case it's needed in the future, he said.

JeffCo Public Schools School Safety Executive Director John McDonald said it's not unusual for Columbine High School to see these sorts of threats.

“This one felt different — it was different and it certainly had our attention," he said.

Closing an entire metro area was not easy, but at the end of the day, they believed it was the best decision to protect students, he said. A student who doesn't feel safe in class can't focus or take a test, he said. While this most recent threat is over, McDonald said he knows Columbine continues to attract people from around the world.

"And if I have any message: We are not a place to come visit if you're not a student," he said. "If you don't have business there, we are not a tourist attraction, we are not a place for you to come gain inspiration."

Frank Deangelis, who was the principal at the time of the 1999 shooting, said he was at Columbine High School Tuesday when it went into lockout. He said the school acted professionally — the students and staff all knew what to do. It was much more reassuring than 20 years ago, he said, and he commended the work of JeffCo Public Schools and sheriff's office.

"It just takes us back," Deangelis said. "And I think (when) you talk to most people who were part of Columbine High School — when that month of April comes, it does something to us all. But we had the support system in place and we take care of each other. We have that famous saying, ‘We are Columbine.’ And during times like this, it resonates, loudly and clearly."

Gov. Jared Polis thanked law enforcement and school authorities for their work.

"As confirmed by the FBI, Sol Pais has been found deceased and the potential threat is over. It’s times like these that help us appreciate friendship, family, and community. Today, parents across Colorado – including me - are hugging their children a little tighter," Polis said in a statement. "Together we thank law enforcement for their swift and diligent actions over the past 24 hours to keep Coloradans safe, and we will continue to be vigilant against threats to our community."

Phillips said the FBI investigation will continue even after Pais' death. He said it appears she was alone, but agents are still following up on leads and combing her social media account postings over the past year to ensure that she had no accomplices.

"It is very important for us to ensure there is no further threat to the Denver community," Phillips said.