There were several streets of old rural-type houses with tall trees (lots of eucalyptus and cottonwoods) to the far rear of Turn Nine, outside of track property, as can be seen (I'm pretty sure that's RIR) in the photo.
But, I was too young to have been at RIR when that photo was taken (1963?) so I can't swear to it.
Mr. "98 SVT - was 06 GT" might be able to help us here.
I wrote on the map of RIR where the houses and trees were. The small red dot is approximately where the Cobra was, but you will need to adjust your mind's compass to look from the north toward the south...the opposite of the map's orientation.