The Endless Sky — Kathryn Lynn Davis

A SON'S DREAM
Phillipe de Vallombrosa is lured to the Dakota Badlands by the same dream that seduced his infamous father--a drive to succeed over the forces of nature in a feral land. He vows to stand defiant against the ruthless enemies determined to destroy him, even as ambition leads him into the treacherous territory of seduction, betrayal, and love...
A WIFE'S PASSION
No longer the untamed girl Phillipe knew as a child, Mianne is now an elegant woman whose poised exterior hides a burning desire for one man--Phillipe. Though her marriage to Phillipe is part of an indomitable family's plan to conquer the vast land, the shared love she finds in the arms of her new husband is as powerful and dangerous as the rival who dares to claim Phillipe for herself...

Heroine: Mianne de Vallombrosa