The litter bothers me, too. It's always surprised me that people go out into nature (whether hiking, horseback riding, cycling, etc) and just TRASH it. Cans and bottles and wrappers all over.
I mean, seriously, where do they think it GOES? Do they think it's just going to disappear once it's on the ground?
Cigarette butts annoy me, too. Not even going to pretend to apologize to smokers about this one - it's your habit, you can keep doing it if you want - but figure out some
way to dispose of the butts besides just dropping them. I don't care if you have to carry an extra empty water bottle with you to drop the butts in. Just pack it out. It's garbage.
A little off topic, but vandalism (of manmade and natural landmarks) makes me bristle. People scrawling their initials or names into rocks or trees, or stealing park signs, or just knocking them down. I don't care who you "love." I don't care what day you visited the park. Sign a freakin' guest book at the lodge or something, don't carve it into a tree trunk or paint it on a boulder.
One of the parks here in southwestern Ohio had new trail markers put up just a few years ago - little colored plastic circles just to help identify the trails. . .and some idiots tore them off and threw them on the ground.
The circles were at "horse height" so I'm fairly certain they were torn down by riders. A hiker probably wouldn't even have been able to reach them easily. It just makes no sense to me. The state of Ohio is already pretty skimpy when it comes to supporting horses in the parks. Depending on who you talk to, some park managers would be just as happy to ban horses altogether, it seems.
And when you see how much some people "appreciate" the trails, by leaving their garbage all over, it's no wonder.