A text I am using has the following sentence,
Trenker stammte aus Österreich und drehte viele schöne Filme über die Alpen.
Why is it über die Alpen and not über den Alpen? My guidance for determining whether a preposition gets declined in accusative or dative is determined by whether it addresses the question "wohin" or "wo", respectively. It appears to me that we are talking about "wo" in this case. Is there another justification for this particular declination?