Extreme Vandals

I've seen vandalism writing on the sides of bridges, buildings, and bathroom stalls, but never before have I seen it on a highway sign. This one is above the road running East/West past Cove Fort, Utah.

First of all, how did they get up there? 

Secondly, what painting is so important that the artist would dangle above traffic passing below at 80 miles per hour?

(Can you read it? What does it say?)