I don’t know what Wright may or may not have said about Mark 13, but in his commentary on Mark Joel Marcus writes that one of the possibilities for the location of the Markan community was northern Palestine and not Rome as many others posit.  I won’t go into the reasons for this area being a possible locale for the community (I’ve listed them in a previous posting), but if this idea is correct then northern Israel near the border of Syria and the Galilean region is very hilly (what the Bible writers would have called “mountains”).  As Marcus points out, Mark shows interest in various places in his Gospel in the “mountainous” Transjordanian Decapolis region of northern Israel.  The Decapolis of Pella is just over the Jordan River in this area and Eusebius wrote that 1st century Christians fled there during the Jewish War of 70 AD.  I think the majority of scholars place the date of Mark after the war and I think this is primarily due to Mark 13 (ie, the author wrote his “prophecy” in this chapter with the hindsight of events that had already occurred).

Marcus lists a lot of circumstantial evidence for his reasoning for this locale and I for one find his arguments compelling although admittedly there are some weak points in it that he himself mentions.  In any event, if Marcus is correct then the original audience for Mark’s Gospel would have known precisely what “run to the hills” meant and it would have meant a flight from Roman persecution.