There used to be a wild crab-type apple tree growing along the fence nearby, between the freeway & a restaurant parking lot. The apples were nothing special flavor wise; but so fragrant that when they were ripe, I would keep one on my dashboard... it would perfume the car for a week. I had hoped to graft a couple branches onto my apple tree; but before I could do so, the parking lot was re-done & the wild tree cut down.
Your story reminds me of my college time at Cornell. At the time I was there, there was not one but TWO wild plum trees I had access to (there were also a TON of apple trees, including the impossible one*, but, at the time, apples didn't interest me much).
One was along the path that ran along Beebee Lake on North Campus, which produced tiny red blushed greeny yellow plums (at the time I assumed it was an American wild plum, but since those are supposed to be too sour to eat raw (which I did with this one) and that they tasted quite a lot like how greengages tasted when I later encountered them, I suspect it may have actually been a European plum that had somehow managed to survive there. It WAS still there the year I took botany (which would have been junior year) since the TA (after I told him about it) brought some branches in for the lesson on fruits (that was actually when I tasted it, someone else did it automatically, and I though if he was OK with it, so was I.) Alas, by senior year, it was dead (no leaves or plums whatever), probably from its terrible case of black knot (which bears out the European plum identity).
The second was a little nearer to my apartment. It stood in a sort of urban tree square on the corner of Seneca Street, one block above my apartment, between another housing complex and a bar. That tree must have been TOUGH, since it was thriving despite having it's base perpetually covered with a thick layer of trash mixed with drunk student vomit (maybe the vomit was good fertilized, but I'd think it would make the soil too acid.) I never knew what kind that was (I think it may have had purply bronze foliage, but can't remember clearly). It produced very tiny plums (most closely resembling mirabelles, based on my later web searches) that were an odd shade of apricot orange. No one seemed to know where it came from (including the head of the department responsible for urban trees in Ithaca, they said it wasn't one of theirs) I never tasted the fruit, but my agronomy teacher did, and said it wasn't very good. That one WAS still there when I left, but I have done Google street views since then, and confirmed that it has long gone (they re-did the area).
The really annoying thing is that I could have kept BOTH going. I left with PLENTY of pits from both trees. But the ensuing years, combined with the difficulties I have had trying to get plum pits (or, indeed any tree seeds, to germinate without either rotting or being all eaten by the squirrels as soon as I plant them has used that whole supply up, as far as I know.
*The "Impossible One" was an apple tree located one North Campus in Ithaca Gorge; about 10-20 feet DOWN the rock face, growing out of the side! The ONLY way anyone would have been able to harvest that one would have been to rappel down the side of the cliff, which no one in their right mind would do (especially considering that the ground on top had a thick layer of muddy loam on it, not great for setting a securing pin (yes, I know that technically, if you're using a pin rather than another person, it's technically abseiling, not rappelling, but the two term are used more or less interchangeably in the US.)
Nowadays, of course, there would be another option; rig up a flying drone with remote controlled scissors and a net or bag and FLY it around the tree. I might have tried that if I was there now (it might be a fun pet project for the Engineering school)
Since no one COULD harvest the apples, I sometimes wondered if, when they fell, they regularly clonked people on the head who were hiking the bottom of the gorge. I hope not. At least one person a year generally died falling INTO the gorge; I'd hate to imagine falling apples adding to the death count (bear in mind an apple falling off that tree would travel about 1500 feet before it hit the ground, so we are talking a pretty hard impact.)