1. Isopleth maps showing above-median concentrations of lead and copper in stream-sediment concentrate, Glens Falls 1⁰ x 2⁰ quadrangle, New York, Vermont, and New Hampshire Yale Public content 1992. 2002-06-01T04:00:00Z. 2002-06-01T04:00:00Z. Geological Survey (U.S.). The Survey ; For sale by map distribution. English. Public. New York (State), Glens Falls Region, Vermont, and New Hampshire.