Grinding / Growling / Rubbing Noise

I live a hundred feet above sea level. When I drive 100 miles to the cabin at 6,000 feet, I hear a grinding noise when I slow to 15 MPH. After a short period of cooling (not driving) the noise is gone. While at this elevation, I do not hear the noise again while driving, or on the way home. It does not occur at lower elevations and I have never heard it anywhere else. Any ideas will be welcome.



Gary

Where does the noise appear to be coming from? Under the truck? Under the hood? Front, rear, left, right?

Any clues at all?

Thanks for the reply. My hearing is not what it used to be, but the noise seems more towards the front of the vehicle. At its worst, I can feel a slight vibration too. I am thinking that the issue might be heat related. The trip requires driving mostly uphill at 50/55 MPH through some fairly tight turns. After the truck sits for awhile, there is no more sound and it does not occur again until the next trip to the mountains.