I was just in the driveway for that pump house yesterday, and there is no road there leading back. However, there was what I thought was a cut clearing leading back and to the right, where your map shows that "lane." I assumed it led to the neighbors yard, and had my kids, so I didn't walk down there. It was well-disguised. I've never noticed it before. Now you have me incredibly curious. However, if it does lead back, it only would lead to the fence, which is apparent even on the map. I can't imagine why it would be there, or that it is maintained in any way.
To be clear, the pump house and the clearing around it are grassy, the woods have dense undergrowth. All I noticed was that there appeared to be a grass pathway cut through the undergrowth. I remember seeing grass on the path - not like a driveway, or a "lane" that is driven on, and path is about as wide as a city sidewalk. I only noticed it seemed to go back a couple feet, enough that I didn't even look closer. Obviously I'll have to now. It was not obvious, as the bushes flanking the path partially obscure it, and I only noticed it because my eyes were following the line where the grass met the undergrowth and in that spot it wandered back into the brush a bit. Hmmmmmm.
Also, after we left that pump house, I took the kids to the park (where we also saw the gramma's sitting with their feet on the cooler). We saw a news crew there about to approach them, fyi...I imagine we were there moments before that pic was taken.
My kids and I wandered over to the playground, that we know intimately. There was a pair of flip-flops sitting right near the merry-go-round. They looked too big for kids, but I think I remember seeing on them, on the straps that go across the top. They looked like someone had placed them (they were lying as they would if put there/taken off there neatly). I just assumed they were left by one of the the multitudes who'd been in that area recently - searchers, volunteers, vigil-attendees, etc. I assumed this area had been scoured, there was literally uniformed and plain-clothes police and FBI within earshot of us.
My wife is off early, and we are planning on taking the kids to the beach (at George Wyth State Park). I may not get a chance to get over there for several hours, unless I run over right now (and I have my 9 & 4 yr old with me).