BOISE -- The body of a young woman who disappeared a month ago was discovered in Boise County Saturday.

The Boise County Coroner’s Office identified the body as 18-year-old Sierra Bush of Boise. Bush had last been seen at her home near Maple Grove and Goddard Sept. 24.

“At this time, the cause of death is still under investigation,” said Boise County Coroner Pam Garlock.

Sierra's body was found in an outdoor location just south of Idaho City. Boise Police say they will work with the Boise County Coroner’s Office and the Boise County Sheriff’s Department to determine how she died.

Police have not said whether they suspect foul play in her death, or whether Bush left Boise of her own volition. But Boise Police Sgt. Justin Kendall said the case is being investigated as suspicious.

“Sierra’s disappearance has been suspicious from the beginning and this is a tragic discovery for everyone who knows her,” he said in a statement. “Every missing person’s case is initially investigated as being suspicious and Sierra was not the type to disappear without telling anyone. For weeks, our detectives have been following up on leads and our investigation is ongoing.”

KTVB spoke to Sierra's longtime friend Samantha McGraw who says Sierra finds comfort in things that are familiar to her.

"I know that she would never run away and she didn't have a need to or drive to," McGraw tells KTVB.

She adds that the whole process of trying to find Sierra since she disappeared has been terrifying.

"It's been heartbreaking not knowing and it's even more heartbreaking now with us knowing where she is. And it's been very hard," McGraw said.

Anyone with information about the 18-year-old's disappearance and death is asked to call Crime Stoppers at 343-COPS.

Police are also trying to get in contact with the person who called emergency personnel about in Boise County about the body Saturday night. That person is asked to contact Boise Police at 570-6290.

MORE: Boise Police search for missing teen

Sierra's family issued the following statement Tuesday afternoon:

"Sierra was a happy and cheerful young lady. She had a 4.0 GPA her entire senior year and maintained a cumulative GPA of 3.82 throughout high school. She scored 1800 on the SAT. She sought out the Honors College at Boise State University and was accepted into the program. She applied for numerous scholarships and was awarded enough scholarship money, based on merit not financial need, that we only had to come up with approximately $500 for her tuition. She had joined the Creative Writing Club and the Beekeepers Club at BSU. Every indication was that she was thoroughly enjoying the start to her freshman year at BSU. When her mother last spoke to her Sierra was happy and in good spirits, there was not the slightest sign of any trouble whatsoever. Sierra was very talented individual and had so much to offer the world in her future years.

"We want to thank all of the people who helped look for Sierra and for the countless hours that they put into it. We want to thank the law enforcement community and especially the Boise Police Department. There were many, many officers and detectives working very hard on Sierra's case, most of which occurs out of sight and cannot be known while the investigation is ongoing. We hope and pray that the law enforcement community will be able to charge, prosecute and successfully convict the perpetrator or perpetrators who are responsible for this crime and bring them to justice.

"Sincerely, Bart and Mary Helen Green"

McGraw also tells us Sierra was talented, passionate, brilliant and a great friend.

"She was just very kind. She didn't have a mean bone in her body. Anybody who needed help with anything, she was there for," McGraw said. "She was just a very encouraging person and I'm carrying that with me."

"She was an amazing person and she is going to be very sorely missed," McGraw added.

Boise State President Bob Kustra also issued a statement Tuesday afternoon:

“The Boise State campus community joins me in grieving the loss of one of our students today. Sierra Bush, known by many on campus as Simon, was an active and involved engineering and Honors College student who left an indelible mark on many students, faculty and staff. It is difficult to lose any member of the Boise State family and our hearts go out to the Bush family and friends who are also mourning this loss. We stand ready to support those in need of services as well as to aid investigators in any way possible as they search for answers to this tragedy.”

A gathering for friends and family of Sierra/Simon Bush is scheduled at 6 p.m. Wednesday in the Jordan AB Ballrooms in the Student Union Building at Boise State.

The teen's family has set up a GoFundMe account to raise money for her funeral. To contribute, click here.