Moffat Tunnel-ventilation system?

UP's Moffat Tunnel in Colorado is one of the longer tunnels in the US. A lot of the other long tunnels have ventilation systems with doors. How is Moffat equipped? If so which end is it located?

Someone mentioned the grade peaks inside the tunnel. That fact would compound any system. Is this fact correct?

East portal has the ventalation.

Does this consist of a door and big fans? Got any photos?

http://farm1.static.flickr.com/23/32741 ... c5a6f9.jpg
Not my pic.
Note the ventilation fan and doors around the portal.