You are looking for a small cache at Margaret Lewis Norrie State Park. For details regarding the Taconic Region Geocaching Challenge, please see MLN #1 Ice Man.
A signalman worked for the railway, and helped manage multiple switches and levers by hand to ensure all trains were moving in the right direction. Once railways were computerized in the late '60s, signalmen were no longer needed, so don’t look for any of them on the tracks below.