The northern summit of Henry Hill has been changed by a gravel mining operation, so the southern closed contour is now the high point. Here are some notes from a local geocacher:
"I survey a bit with my work with C.T.Male Associates, P.C. in Latham, NY and geocache for recreation. Geocaching has taken me to the highest point in Albany County, which is called Henry Hill. I visited the actual (apparent) highest point and found it to be different than the point listed on the site.
The Henry Hill listed has been mined over time as a gravel pit and has been radically altered and lowered. I did some research and found info on the "apparent" new high point, which I visited in the field and recorded a waypoint for. It is an indistinct high point in the pine and hardwood summit of a hilltop found about 0.30 miles SE along an azimuth of 145° True from the Henry Hill listed.
This is the Lat/Lon I recorded using my Garmin Map60Cx, WAAS differentially corrected, and using an external antenna for the best results. I averaged the position over a 20 minute period. The elevation is not considered very accurate but should be +/- 20'. The point I took is my guess at the highest point on the hilltop which is tree covered with no views and is gently sloped in all directions. There is no distinct summit, and it is rather unremarkable I must say."