The Enchanted Land by Jude Deveraux

Headstrong Morgan Wakefield makes a devil's bargain with handsome rancher Seth Colter to lead her through untamed territory. From the bluegrass splendor of her Kentucky home to the rugged beauty of sun-drenched New Mexico, golden-haired Morgan comes to realize the passion and inner fire that are a part of her soul. Her journey is riddled with hardships and cruelty, and is fraught with misunderstandings...but it is with Seth under the blazing Western skies that she discovers the burning intensity of love. From a Spaniard's captive to a land baron's wife, Morgan endured, for always she held in her heart the beloved caresses of the man who defied a continent's dangers to possess her.