Yup, Pineridge runs a little further south (but your sketch is close enough for Government work) and the network of Michaud trails ends up off the map further north, just even and a bit north of North Dam.
The Grey tail I believe is on CDC or CSU property and I thing it is on Private property. I see a lot of runners on it though, so it might be legal???
Also, "shoreline trail" has a bunch of offshoots on the west side of the road and is a pretty good little trail network if you loop it up a bit and don't feel like heading all the way north and exiting Michaud Lane. Sometimes i'll ride Pineridge - Maxwell - Shoreline - Michaud/Baby Head - up Michaud - back to Shoreline then back down Maxwell. Less road riding back on Overland Trail.
BTW, did you guys hear Overland Trail between Mulberry and Michaud will be closed from early May until August? They are doing major road improvements which includes a 6 foot bike path on both sides of the road! Very cool...