I'm a Sacramento native, born in 1960, and I grew up surrounded by dim stories of Vaca Valley Raceway. My father was a British Motors mechanic for a time right after the war, and was a car-crazy, race-crazy kid until his growing family made him put it mostly aside sometime before I was born. (Having a good friend killed in a gruesome race accident didn't help... my mother told stories of the bloody leather jacket my father kept in the garage until she made him throw it away.)

About 1980, there was a nice essay about it in Car and Driver, and inspired, I went to the site. Like Dann Shively in your posted account, I simply walked through an open gate and walked the track. It was in somewhat better condition then but still turning to gravel. The east curve of the road course was all but gone, but I walked the oval and the west loop of the road course. The painted starting grid was still visible on the asphalt. The drag strip, which was used until the early 1970s, I believe, was in somewhat better condition.

I've been a number of moving places in my life, but standing on that fading track in the morning sun, pacing off the numbered starting grid, I was surrounded by ghosts. I could hear them all - the Vettes, the Mercs, the Coopers, the Jags, howling past me in the silence. I took some pictures, but they were on 110 cartridge film with a crummy 
Instamatic - the slides are still somewhere in a box, but I have no idea if they're even usable after 25 years. I'll have to dig. I recall some nice shots of the grid and numbers.

Tonight I was playing with Google Earth, and thought to go look... and there it is, the old ghost. The imaging is maybe five years old or less, but you can see the whole track, east loop included, and zoom in until you can nearly see those grid numbers. 

I slow and look for the banked turns and the rusting rows of crash barrels every time I drive by - perhaps 3 or 4 times a year - and it always gives me a shot in arm just to see it still there, almost completely forgotten but dreaming of its glory days.

For a little longer, anyway. The last time I drove by, I was saddened to see rows of heavy equipment ready to go to work and the unmistakable signs that yet another office building, industrial park or retail zone was about to be added to the planet. I have no idea how the track survived these decades, but its time is almost over - 
it may even be gone as I write this."