Heartland On the Side of Angels by Terri Sedmak

Adventure and romance will not be denied anyone who has the courage to be free. WYOMING, 1883… When twenty-year-old Kelley Keaton returns home after five years in New York, she discovers home is not the place it used to be. Her brother is behaving mysteriously. Her childhood nemesis, Luke Taylor, is now connected to her by a controlling organization their families created and call the Alliance. And their neighbor has turned being a nuisance and a bully into something far more sinister and menacing.