I recently visited Gangtok(North SIkkim too). Have visited Ladakh twice.
Most of the tourists are not aware of basic etiquettes. and so sad.. many of them are educated.
Ex: Throwing plastic bottles, plastic covers etc on road(literally wherever they want to throw).
And, at NJP railway station, there was a train with many CRPF staff(Going for an election duty, I guess).
I felt very bad after seeing them, doing similar things. (Throwing almost everything on railway platform).
I observed, there were few dustbins and really empty even after the train left(I believe, There were about 1000+ CRPF members in that train).
“No plastic campaign” is very much needed to keep the places clean(The high passes, where more people might start visiting).
Just similar to Dow causes, it would be good if “No plastic”/keep it clean awareness is available in DoW website.