can you give a general idea of the geographic location
East of San Jose and west of Merced.
A few seconds after I saw it I noted the reading on my odometer. The first exit on I-5 (going north) past the tree is exit 428. According to Google maps that is Fink Rd. Milepost (if there were any, there aren't) 425 is about my estimate of where the tree is, based on what my odometer said. I looked for a Google street view that might show it, but found none.
The general terrain is bare except for some orchards. The tree has that grand sweeping stature of an old oak, with one large limb sweeping down to the left (when viewed looking east from I-5) and back up again. However, I don't think it's an oak because it has very light, whitish, bark. Not a eucalyptus which wouldn't have that structure anyway. There were several trees in a group with the one being very prominent. All within 75 yards of the freeway as I recall.