I would bet money that your High Country has heated mirrors. My '03 LT has heated mirrors. They're a little tricky though as it's not super obvious how to turn them on, but they should come on when you turn on your rear window defroster. Give that a shot and let us know how it goes.

 

Yes, heated mirrors should very well be part of any of the higher trim levels.

As kdducttaper mentioned, the heated mirrors will be automatic whenever you turn on the window defroster.
There is no separate button for them.

 

Yep the heated mirrors were tied into your defroster to cut down on redundant buttons and make room for more😆

 

Heated mirrors have been linked to the rear window defroster for years.

2011 owners manual

2004 owners

2004 is the oldest one I have an electronic copy of.