Valley of Promise by Kari Trumbo

Armstrong has never had a choice in his life.

Pa has made every decision, from who his friends are to when he will take over their huge cattle spread. He’s made plenty of enemies in Belle Fourche, SD along the way. Especially their neighbors, the sheep ranching Johlmans.
When a judge arrives in town to look into all the misdeeds of both families, Armstrong’s carefully planned world begins to crumble, particularly when he meets the judge’s daughter. A woman who could have his heart, unless her father finds out what his family has been doing.
Dosha Cattrel’s father has threatened every man who’s shown interest. She’s given up hope of ever finding someone perfect enough to suit him, much less love her.
Her father brings her and a secretive Pinkerton agent to investigate a land war. She fully expects to be bored silly until she meets Armstrong, one of the very men under her father’s spyglass. What Armstrong doesn’t know is that she is related to the Johlmans, his fiercest enemy.

Can a forbidden love survive the light of day, or will secrets kill the growing love between them?