Haunted Hills by Taylor Manning

Ex-Dallas detective Sara Barrett doesn't exactly believe in ghosts, but she doesn't not believe in them either — until she has a disturbingly sensual encounter with the long-dead owner of her newly acquired ranch, cowboy Quinn Farrell. Quinn is a soul unwilling to rest. Now, nearly a century after he was betrayed by those closest to him, he is determined to keep everyone off his land. Quinn can only materialize in two places: the cave where he was murdered and the bedroom in the old house where he was born. The same bedroom where Sara learns that it's possible not only to make love with a ghost, but also to fall in love with one. But little do Sara and Quinn suspect that a crooked land developer will use any means, even murder, to get possession of the ranch they both love.