It actually seems strange he has not; he sounded so confident in that approach on the campaign trail.
https://www.msnbc.com/rachel-maddow-show/maddowblog/national...
(... ironically: to the extent those parks have a trash problem, it's because Trump's administration cut funding to the park service (https://www.americanprogress.org/article/the-trump-administr...), which maintains those parks directly since they are federally-owned).
But it is interesting to observe this administration, which ostensibly is anti-waste (given the started goals of DOGE), replacing park service employees with far more expensive Marines on deployment for something as far from national defense as trash duty. Unless those scraps of candy wrapper and discarded straws are packing a lot of firepower these days...
I'm just saying, if he's going to deploy them for trash duty, why not deploy them to rake the forest floor like he said someone should do? Especially since his administration is currently pulling active firefighters off the front lines of fighting a fire because they've decided that deportation is a higher priority than protecting American property and lives (https://www.cnn.com/2025/08/31/us/washington-fire-detain-wor...).