Asturias is correct - Billings Logan International Airport (KBIL) in Montana. An unforgettable airport once you've seen it. The cliffs are known in Billings as The Rims, which overlook the city in the north and east. They are formed by the Cretaceous Eagle Sandstone.
There is an ongoing issue with rock falls, causing damage to houses that have foolishly been built close to the foot of the cliffs. I hope none of those houses were bought by civil engineers or geologists!
Asturias has control