An Ely man has been sentenced to 25 ½ years in prison for kidnapping and raping a 15-year-old girl.

Authorities said David Alan Nielsen, 35, held a knife to the victim's throat before repeatedly sexually assaulting her in a gravel pit outside Ely in November 2017. He pleaded guilty last month to felony charges of third-degree criminal sexual conduct and kidnapping.

Sixth Judicial District Judge Gary Pagliaccetti on Monday sentenced Nielsen to 177 months for the sexual assault charge and 129 months for the kidnapping. He ordered the prison terms to be served consecutively, followed by 10 years of conditional release.

According to court documents:

Nielsen pulled up to the girl, who was known to him, in downtown Ely and offered to drive her home after she'd parted ways with a friend on the afternoon of Nov. 20, 2017. The girl agreed, but he passed her house and told her he was going to "teach her how to drive."

Nielsen drove the girl to a gravel pit outside town, where they did some doughnuts and swerves" as she sat on his lap and steered. After stopping the vehicle, Nielsen pulled to the top of a mound and told the girl, "Let's watch the sunset."

Nielsen made the girl kiss him, she told police, then forced her to lie down on the seat. He proceeded to hold a 6-inch, non-folding knife stamped "U.S." to her throat and told her to "be a good girl."

After putting the knife away, he made the girl take off her clothes, before forcing her to have sex "five or six times," she reported to police. When it was over, Nielsen drove the girl home and told her he'd kill her if she told anyone, while also threatening her family and friends.

Upon arriving home, the girl told her mother what happened and went to the local hospital. During interviews with police, the girl described a broken glove box and cracked rear view mirror of the vehicle. She also described how Nielsen used at least two condoms and disposed of them in a Marlboro cigarette pack before lighting the pack on fire.

Investigators with the St. Louis County Sheriff's Office later found burnt material near both tire and footprints on top of the mound in the gravel pit. The next day, officers used a search warrant to locate a silver knife with a "U.S." stamp in Nielsen's duffle bag.

A search of Nielsen's vehicle also produced unopened condoms and a partial wrapper similar to the condom packaging. They noted the vehicle's glove box was broken and sitting at an angle.

Nielsen must serve at least two-thirds of the prison term before he is eligible for supervised release. He is currently incarcerated at the Minnesota Correctional Facility in Rush City, with an anticipated release date of November 2034.