Aamadmi said:There are inland offices that you can go to. They can validate your PR as well. You dont need to cross border to do that.
http://www.cic.gc.ca/english/information/offices/help.asp
You don't need a US visa....you just need your passport and COPR....when u reach US border let them know you are here for landing...they will check ur passport and COPR and redirect you to canada...and then there you will get landing paper which they will attach with your passport...