[sanghill]

I paid $2680 for the Subaru Extended Service agreement.
Put that amount of money in an interest bearing account of your choice. Consider yourself 'self insured'. If you never need it, you will still get your money back.
You drive in the real mountains, I would call that 'severe' even if you don't go off road. Follow the Severe Service Maintenance schedule in the Maintenance and Warranty book, the Warranty section specifically. Verify your local dealerships on dealerrater.com, you may need to find a more qualified independent Subaru repair shop. Refer to this and the other Subaru Forums, there is lots of great information.
Changing the engine oil and filter every 3k miles per the Warranty book, implies to me that Certified Subaru engine oil isn't all that great. Use a quality synthetic brand of engine oil and change it every 6k miles. I use Amsoil Signature engine oil. You will probably want to use 0W-20 oil since it tends to get really cold in the Winter. Tends to get really hot also, been there.