Alaska State Troopers say a 16-year-old girl was fatally injured Saturday afternoon on the Seward Highway near Girdwood, in a single-motorcycle crash that closed the highway for hours.

Troopers responded to Mile 91.5 of the highway, just north of its junction with the Alyeska Highway, at about 3 p.m. according to an online dispatch.

“Investigation revealed [Emily Tredway] was driving a 2013 Honda motorcycle traveling southbound on the Seward Highway when she lost control and struck the guardrail,” troopers wrote. “She was transported to the hospital in Anchorage where she was pronounced dead.”

Tredway was a junior at South High School, according to a family member. They said she was out with her dad enjoying one last ride in the nice weather.

The 16-year-old's family says she was an avid and experienced rider who was certified and has even ridden across the country.

KTVA was told she was an honor student already looking at colleges.

Her family describes her as a "ray of light" who was "so loved".

Troopers are still investigating the cause of the crash.