I think these westerns and Star Trek and others were filmed on the same ranch in the SF Valley or just north where the Manson gang held out for awhile.
The rocks where the LR and Tonto ride around are the same where Kirk fought the monster mano a mano, IIRC.
Kirk did most of his fighting on a closed set.
They had to keep turning the fake boulders around to have them look a little different.
Hahahaha....and that stupid music was playing in the background as they struggled! You have to admit, when even a kid looks at a cheesy reptilian head and thinks..."Oh no...The paper mache head is going to kill Capt. Kirk!" then your special effects department needs help!
(One of my favorite movies is "Galaxy Quest"...they NAIL it!)