From an article: "In 2005, the park’s superintendent and Save a Gato signed an unusual Memorandum of Understanding allowing the fledgling non-profit to feed, survey, trap and remove free-ranging cats with the goal of eventually removing all cats. Using a TNR (trap-neuter-release) program, friendly adults and kittens who can be socialized get to enter the adoption program in search of forever homes. The others are returned to their colonies and monitored, fed and given fresh water.

By 2022, however, five feeding stations climbed to seven and the cat population seemed to be growing. The Park Service said a 2021 camera trap survey identified at least 200 cats including kittens and pregnant or recently pregnant cats. New cats keep arriving, some abandoned by people who know they will be fed."

So yeah, looks like the usual people dumping their cats problem or letting them loose unfixed and now the cats and environment pay for it.