This sign is from the Chickadee lift in Snowbird.
It says:
Protect Your Drinking Water. Keep it Pure. Please use Restrooms.
Because apparently they have a real problem with public urination and pee contaminated water.

Blankat found this sign at Breck.
Employees must wash hads after enjoying a big dump.

This trash collector at Mountain Creek says
Don't dirty Jersey
Pretty sure that it says Dirty Jersey on the New Jersey flag...........
Remember that SNL skit where a fake blind governor guy makes fun of Jersey?
That's the best.