This is my home.
When I was a kid (90s) we had MANY rabbits running around. My first memories of shooting are sitting with data and an old single shot .22 and popping rabbits like it was a shooting gallery. He said at the time it was nothing like his childhood (late 60s), but that it was still pretty fun and I know they were plentiful.
By the mid 90s they were in rapid decline, not due to fox. Must have been some kind of disease. I never saw a fox up there until probably 2000ish. All of a sudden there were black fox everywhere. Someone certainly brought them in, but nobody ever spoke of it.
Now days the population is normal. It is higher out at American camp, but the days of thousands of rabbits running around San Juan Valley are over. We see an occasional rabbit here or there, but nothing like the days you speak of. Occasionally in the early 2000s a nearby neighbor would buy us shells and we'd take out 50 in a weekend (spurts of the good ol days), but I have no idea where you'd find that now as even then it was extremely rare.
They were a ton of fun for target practice though, never cared for eating them too much at the time.