How do you taper for a marathon at 11,000 feet?

[Lauren Jones]

I am preparing for the Leadville marathon-  my first marathon ever. 
I know, crazy huh?
But when I do something, I like to go all out!

I only have 2 weeks left until the race, my question is what kind of taper do I do?

I still have yet to run over 20 miles, should I go for it this week?

HELP!!