Trouble at Gunsight, copyright 1964, is the other half of the Ace Double with Trail Drive.
Louis Trimble, author of many westerns, created a tense plot in this one. Set around the area of Reno, Nevada, at a place called Gunsight, his main character, Cole Pender, received an offer to buy half of the Tepee Ranch and sets out with a herd of prime graded beef with his two ranch hands, Julio and Nito, a father and son pair of cowboys who would do anything for Pender. It is the area where Cole grew up and he is looking forward to returning to Gunsight Valley and the Tepee. He makes a quick trip to Reno and receives an anonymous note to stay away from the Valley and never return. Of course, he continues on and is ambushed twice as he nears the valley and runs into his childhood acquaintance, Chad Leeman, who warns him to stay away. He and Chad had a knockout fight that Cole remembered and never considered Chad a friend after that. Throw in a newcomer to Gunsight, Raul Horneman, and a couple of gunfighters, Riddell and Parker, and the plot thickens. Add his old girlfriend, Myra Callahan, and her brother, Allie, who has never grown up but is now a deputy sheriff under Sheriff Mullan and it gets thicker and thicker leaving many questions unanswered, like who was behind the ambushes? Who is this feller Horneman, who seems to be a friend of Myra's?
The story continues on and Cole is almost killed in the various melees that take place as he falls in love with Myra, and it races to an end with Cole's questions being answered on the mountainside above the valley in a gun battle to the end.
Don't remember reading other books by Mr.Trimble, but found this one to be just fine and entertaining. Recommended, a four-star novel in my internal grading system.