Beartooth Betrayal by Millie Vaughn

She chose to trust him. That choice could get her killed.

Brooke Davies does not let go. When something matters, she holds on until there is nothing left. While training for an ultramarathon, her world turns upside down when she stumbles on a grisly discovery deep in the wilderness.
Tyler Gillis knows heartache. His perfect world was shattered by the deaths of his wife and child, and the allegations that followed. Now he is ready to set the record straight, but someone else has different ideas.

As bodies from the past begin to surface, Brooke is caught between what she knows and what she feels. Every instinct tells her Tyler is not a killer, but trusting him could make her the next victim.

With a relentless deputy closing in and a murderer determined to keep the truth buried, Brooke cannot walk away. Not from the truth. Not from Tyler. This time, her obsession might be the thing that gets her killed.