Zechariah 14

And in that day His feet will stand on the Mount of Olives,
Which faces Jerusalem on the east.
And the Mount of Olives shall be split in two,
From east to west,
Making a very large valley;
Half of the mountain shall move toward the north
And half of it toward the south. v.4

Read chapter 14
This chapter is all still of time yet to come the first half of the day of the Lord in the end of the tribulation time and the second half ending this book with life in the New Heavens and New Earth.  This first part seems like an intense action movie.  God's described as standing on top of a mountain and it splitting in two to make a path in a valley for Israel to flee from the antichrist as we see commanded in Matthew 24 of the tribulation time, “Therefore when you see the ‘abomination of desolation,’spoken of by Daniel the prophet, standing in the holy place” (whoever reads, let him understand), “then let those who are in Judea flee to the mountains." (vv.15-16).
I guess if God can split the Red Sea why not split a  mountain?  Plus we also know that Christ will return to the same place He was taken up as we read in Acts 1 of His ascension, "“Men of Galilee, why do you stand gazing up into heaven? This same Jesus, who was taken up from you into heaven, will so come in like manner as you saw Him go into heaven” (v.11).  They were in (or around) Jerusalem which the Mount of Olives was near.
This is Christ's second coming, but this is not what we are waiting for as to what's next in God's order of events for many things must still take place before this event.  
The command to flee to the mountains is for the Jews living in Jerusalem in this future time, but oh how we wish today that God would open up a mountain for us to hide in from our enemies.