They found my sister under the ice with stones tied to her feet.

I am Margaret Hartley, and I have not slept through the night in seven years.

This is the story of Emily Hartley, and how a Montana river finally gave up its darkest secret.

Emily was 27 years old, a graphic designer from Portland, Oregon.

She loved the outdoors more than anyone I ever knew.

Every single weekend she hiked Mount Hood or walked the Columbia River Gorge.

She would come home with mud on her boots and a smile that could brighten the entire city.

Emily had been dreaming about Glacier National Park for as long as I could remember.

She had posters of its blue lakes and rugged peaks taped to her bedroom wall.

She would sit on the floor and trace the trails with her finger.

One night she looked up at me and said, ‘Maggie, I’m going to hike the Flathead River trail. I have to see it for myself.’

I remember the exact tone of her voice.

It was not a question.

It was a promise she made to herself.

For months, Emily planned the trip like it was a military operation.

She studied maps of Glacier National Park until the corners were worn soft.

She read hiker reports and trail reviews online.

She bought a new backpack, a water filter, a satellite messenger, and the sturdiest hiking boots she could afford.

She packed and repacked her gear at