At sea level water boils and turns into steam at 212°F but water will boil at lower temperatures at higher elevations.
Boiling Points at elevation
Sea level = 212°
2,000’ = 208°
5,000’ = 203°
7,500’ = 198°
10,000’ = 194°
Altitude will have a larger effect on baking and boiling foods than on roasting but you may have to roast that turkey a little longer at higher elevations. Adjusting roasting time at higher elevations can be a bit tricky and a meat thermometer is always a good idea. At lower elevations, a temperature in the thickest part of the thigh of at least 165°F should indicate a done turkey.
At elevations say above 4000 feet, you may need to add add approximately 5-10 minutes per pound to recommended roasting time @ 325°F. Use a meat thermometer to check doneness. A temperature of 180-185° in the thickest part of a thigh for a whole turkey should indicate a fully cooked bird at higher elevations.
Checking the temperature often near the end of the cooking time will help in pinpoint when it is ready to eat. Another thing to consider is that at higher elevations many times the air is much drier. Account for evaporation and keep that bird basted. Happy Thanksgiving to all from sea to shining sea.