Hello Kesterlester, great to hear from a fellow OSMer... My approach has been to identify utility markers on google earth firstly. Then, as I am relatively local as you say, I have done some additional recce with the old binoculars that can sometimes pick up more distant ones! Also, there are lots of clues from aerial photography, so tell-tale gaps in trees and sometimes crop marks indicating the lie of the pipelines!. So its a bit of detective work combined with educated gesstimates! Hope this helps!