I can't say about confusing a coyote with sound in Mountains. My experience is in foot hills. Some very high others small & undulating.
I suspect in mountains. If you keep your call or caller going[continous]. A coyote will soon zero in on it's coordinance. Regardless of the echo'ing.
In hills, if a coyote is down low in a valley. It will take them abit longer to I.D where a sound is coming from. As the sound echos' over & around them.
However, if they are up high on an adjoing hill or hillside. They can pin-point the sound's coordinance, in the blink of an eye.