Mustang Men — Thorne Douglas

He had been a horse thief once. His name was Shan Tyree, and sometimes it seemed that he'd known nothing but trouble all his life. Coming into Texas, he encountered Rancho Bravo and found what he'd been looking for. A place to belong, where he could use his abilities on the new horse ranch being put together. Then a new passion emerged. The manager was married to a younger woman. A connection was there, but Tyree was determined to play it straight.
When the old partner turned up, after the fine Spanish herd they'd bought to upgrade the wild mustangs they were gathering, it screwed up everything that had been going Tyree's way.
He didn't like the threat to his new way of life.