There was no connection between Cellar Mountain Road and Moose River Road along the Silver River until the Conservation Department built the connection in the late 1950s before acquiring the lands due to the parcels being owned by different companies.
The remote Sly Pond is one of the highest bodies of water in Adirondack Park at an elevation of 2,872 feet. It was once infamous for being a marker of how acidic Adirondack lakes had become by the eighties, with the DEC recording in 1980 the pond having an acidity of 3.54 which is about as "acidic as a dill pickle".
https://www.upi.com/Archives/1981/05/10/Acid-rain-damages-are-reported-in-Northeast-Canada-Far-WestNEWLNNew-York-suit-tries-to-prove-source-was-Midwest-plants/1857358315200/
I've been working on some neat 3D maps an animations using QGIS 3D mode, including this historical map of the area around the Moose River at Moose River Plains.