A few day's ago, I asked "what Trigger this was", and nobody answered, so I will tell you. It isn't this is Pal

Dale also had a palomino named Pal that she used in personal appearances around 1950.
She used this horse in a pilot film that she made for television, Queen of the West. This show never aired because Roy made the decision to go into TV in 1951 and Dale joined him in the highly successful and long running Roy Rogers Show. She didn’t use Pal in that show because he looked so much like Trigger, it was felt that the audience would get the two horses confused. Randall found a nice buckskin Quarter Horse, Buttermilk, for Dale to use in the show.

As a side note, Glenn earlier had looked at a beautiful chocolate colored horse with a white mane and tail for Dale to ride but determined that the stallion was a little too spirited for her to handle comfortably. When Rex Allen was looking for a picture horse, Glenn remembered the chocolate horse and told Rex about him. Rex bought the horse and he became Koko.