I'd say 4,000 feet sounds bang on (or maybe the 3,800 mentioned by others). What I liked about the route was that it was nire on runnable all the way apart from the short climb from a reservoir early doors and that final short sharp steep bastard at the end.
I too went wrong near some kind of building not before checkpoint 13 - I was following a Clem runner along a main path but then realised he'd hacked off to the right through the tussock grass and swamp land, with all the other runners behind me having veered off a couple of hundred yards back. I have no idea whether there was an obvious trod that I just missed or not or whether this bit was down to just taking a line. Having not run or recce'd the route I was largely depending on being able to follow others

. The thing is I just assumed the Clem runner had screwed up and, rather than continue to follow him, I took a cut my losses line through some awful stuff to join a trod being followed by the rest of the race. Needless to say the Clem guy ended up taking a difficult but faster line and probably did know what he was doing! Drat and double drat!