Establishing the dates of construction of depot buildings of the original and subsequent replacement/major rebuilding, establishment of flagstops/scheduled stops is difficult.
Timetables (ETT, public, suburban) are a guide but don’t always show all the locations. Tariff filings are a possible source of data but they might not exist anymore.
Local historical societies often have garbled accounts of what actually happened. Even railroad records are not 100% as I’ve found conflicting information.
Unfortunately not many of the papers transferred to the Newberry Burlington Archives are engineering orientated and deal primarily with finances. The 1922 General Office Building fire wiped out a lot of history as only then current property was redocumented.
On Nov 26, 2020, at 1:52 PM, cbqbill1x <kybillhusb@xxxxxxxxx> wrote:
According to the information I have, the Highlands depot was built for a private owner in 1873. The photos below provide a great deal of detailed information on the station. No dimensions, but still valuable. The Highlands Station was operated as a flag stop from the date of its opening until 1904, when it became a regular stop. 
Note: The Highlands Station is listed as "Hinsdale" in the attached list. Records shaded in green have photos available, and records shaded in red/orange are historic records.