SO THIS is the location I was refering to - Vasquez Rocks Natural Area and Nature Center, Sierra Pelona in northern Los Angeles County, California - it was used in several different Star Trek TOS episodes, and as I stated I realized MMPR original series pilot & several other episodes were filmed in/around the same location - and I ALSO just realized some of Lost In Space 1965 Season 1 were ALSO filmed at the same location as well as COUNTLESS various movies over the years
@duglop I used to go up to Vasquez Rocks on the regular most every summer, just to hike around and dig the scenery. It was only about 40 minutes from where i lived in the San Fernando Valley.