Continuity mistake: After the horse race with Sam, Elsa and Sam are talking with bright high sun and shadows on Elsa's face. Moments later the the sun is low on the horizon in clouds. Then later in the same scene the sun is high and the strong shadows are on her face again.
Continuity mistake: When the trio encounter the law officers from the Wyoming Stock Growers Association, it starts snowing while they're talking to each other. After the gun fight, it's sunny.