Can you Disable Engine Shut off at high altitudes (350 econoline van)?

We have a 350 Econoline van and on a trip to Allegheny Nat'l Forest in PA the darn thing just stopped running. Wouldn't even turn over. Eight hours later we had it towed off the mountain, out of the forest, and it began to run fine. A friend suggested it might have some sort of altitude cut off 'switch' and I was wondering if this is the case how do I find the darn thing and disable it!

Any suggestions would be appreciated!
Thanks!
C.

A friend suggested it might have some sort of altitude cut off 'switch'.
Vehicles do not have such a feature. There would be massive legal liability issues if a vehicle was deliberately designed to stop running without warning and for no good reason at all.

How is the van running now? There are several reasons why this problem would have occurred. When it would not turn over, did you lose all electrical power (no lights etc), or did the engine seem like it seized up?