Wolves of the Sundown Trail

"Wolves of the Sundown Trail: Duncan Innes, a Scot trapper fled Kentucky to escape the curse of the MacAlisters, a feud that began centuries before in Scotland and was transported to the New World when descendants of the two clans emigrated. Innes's lonely camp is invaded by John Ryker, a trapper, and his guide, Wisapa, a Dakota Indian, who are seeking a map to the Lost River and who don't intend to let Innes stand in their way."
"Buckskin Border: Shade Cameron is an undercover agent for the American government. He is shot by Hidatsa Indians while investigating why American agents have been disappearing in the area. Things get worse when he meets up with two French-Canadian voyageurs - who try to finish what the Hidatsas failed to do."
"Duncan Innes thought he could escape the 500-year-old curse the MacAlister clan put on his family back in Scotland by becoming a trapper in the wilds of America. But in only a couple of years, Innes has lost two partners and now a man named Ryker is threatening his life if he doesn'thelp find a legendary spot supposedly teeming with beaver."
"The lash of Señorita Scorpion: U.S. Senator Warren Bailes was shot down in the street of Alpine in the Big Bend area of Texas. According to witnesses, the senator was assassinated by Elgera Douglas, commonly known as Señorita Scorpion. U.S. Marshal Powder Welles has been assigned to arrest the Scorpion, but to do that, he has to find her first."