That's the top end of the dragstrip — those white objects at top right of the track are three-story-tall buildings with media, sponsor, track and sanctioning body facilities. The buildings form an archway which the cars roll under into the staging area. I suspect you're right to assume that property to the northeast belongs to somebody else. Given that the cars roll into the staging area under those buildings, nothing less than a total reconstruction project would be needed to re-do that end of the track.
If you look down at the other end in
Google Maps (drag the map down to see the bottom end of the track), there's a long asphalt runoff area (necessary) but a short gravel pit with a grassy stretch behind it; after that there's a concrete barricade/fence combo and some trees at its end. There's a public road called Pension Road behind the pit. The asphalt runoff area is longer than the 1/4-mile track itself, probably close to half a mile, but that's not enough room for an out-of-control 300mph vehicle to slow down. The gravel pit is way too short, from what I'm looking at.