Yep. Precisely The chances of breaching Cheyenne complex is near zero. Here's why: The mountain face is pure granite atleast a quarter mile thick above the bu

Yep. Precisely The chances of breaching Cheyenne complex is near zero. Here's why: The mountain face is pure granite atleast a quarter mile thick above the bunker reinforced with steel inside. To breach even 100-odd meters, you need a sufficiently strong impactor on top of your warhead which is made of lead or similar grade material. That drastically reduces the payload of actual weapon. If you choose a cruise missile, none of them have sufficient range & also again weight limited in the neighborhood of 1000kgs. If you really want to bore a hole through with multiple impacts, you would need a dozen warhead hitting the exact same spot. CEP of best missiles are still ~10-100 mtrs in the best case. You can do the math how probable is the event something will breach Cheyenne Mountain complex. To add to another separate comment, NORAD still keeps backup operation alive inside the cave complex (source: Wikipedia). This is in the event a hostile situation disables Peterson AFB.