I've been wanting to make a sticker to throw on my blazer that says:

Help keep our trails open and Tread Lightly


Am I going to run into any copyright laws or anything?

It is a registered trademark so it could pontetialy get you in trouble. but the odds, as long as you are not going to make 100's and sell them, are slim to none.

Practice what you preach and I bet that they wont mind.

my .02$