Joel McCrea was wearing a waistcoat talking outside saloon with two buddies. When they entered the saloon seconds later, he was not wearing it. When he eventually leaves the saloon, he walks towards the door and is next seen by his horse and is wearing his yellow waistcoat again.
During the first night of the cattle drive, Cord and Ralph have a conversation on horseback in which Cord tells Ralph that the moon is coming up. But the previous scene showed a brightly lit night sky, as if the moon were already high in the sky.
At the start of the movie as John Cord is lying in the street after being dragged around, the Hamiltons walk up to see what is going on. When the view cuts to close ups of Cord in the street, you can clearly see the green dress of Janice Hamilton right next to Cord. Yet when they go to pick him up, they have to walk several yards to where he is.
When McRae is originally contracted as trail boss the herd is said to be 5,000. When McRae stops some of the townsmen from turning back he states he was contracted to deliver 4,000 head. When McRae informs the other herd owner Garth that he is going to work for the town's herd only because he can't lead 5,000 cattle to their death by going to Dismal River which is dry. When McRae is ready to leave the trail drive at the end he presents the trail log showing they lost 182 head out of 4,000.
At 54.00 minutes into the film, the cowboys are sitting around a campfire and the character referred to as 'Wrangler' asks one of the Vaqueros for 'aqua', Spanish for water. The Vaquero picks up the coffee pot and pours coffee into his cup.
At around 36:30 you can clearly see huge power poles in the background.
The final shootout between the trail crew and Garth's men is done exclusively with pistols by all participants. McRae had a rifle earlier when he quelled an internal rebellion of his crew. Garth recruited gunmen to help him steal the cattle herd and none of the men going to the gunfight or ambush used a more accurate long distance rifle. Before and after the shootout Garth clearly has a rifle in a scabbard on his horse.
Cattle drives had scouts doing advance searches for water and grass that were planning routes days of travel ahead of the drive. Neither of these two cattle drives bother with advance scouting which is a major risk of death from thirst to both herds. One of the herds perishes from lack of water after the decision is made to go to drive the herd to a dried up water source.
Bing Russell's character is supposed to be young and inexperienced but Bing was over 30 at the time of the movie.