Any high altitude eggers out there??

A dome of 220 will put your grate at 190-195. Ribs are cooked around 185-190 though it is damned near impossible to get a valid temp do to the proximity of the bone to the temp probe. It will take quite some time to cook at 220 dome even at sea level. Having said that.

Sea Level or High in the Andes 220 degs is still 220 degrees. Altitude affect foods that require boiling water to cook. Water in it's liquid form will not exceed boiling point. Even the steam will be lower in temp the higher up you are. At your altitude water boils at around 200 and not 212. So food takes longer to actually cook because the timing is based on 212 degs.

Kick the dome up to 250 and you should be in the ball park. From 250 kick it up 5 degs. each cook till you reach the same cooking times we have at sea level. For Rib that should be 4-6 hours.

I live in Pueblo, and even here I cook ribs at least 250. It does take about 20% longer. I always use water in the drip pan and foil at the end. Never had a bad batch. Keep on trying.