A 37-year-old female backpacker from Battle Creek, Michigan, died of unknown medical complications while hiking at Isle Royale National Park on Monday.

She was hiking near LeSage Lake when she suddenly became unable to walk, lost consciousness, and stopped breathing.

Despite CPR efforts, she could not be resuscitated.

Due to the park’s remote location, a ranger and EMTs stayed with her and her partner until her body could be transported the next morning, NBC News has reported.

The investigation into her death is ongoing.

Written by B.C. Begley