This brochure was from the early-mid 1990's. We used the same one for a few years with couple of changes here and there. The clue is the operating days are shown as Memorial Day to mid-October - with no specific dates shown (for multi year use that way).
Kyle started changed from starting mid-June to Memorial Day in 1990 or so. When Corporate told us this we told them about the snow problems
(Kyle opened Memorial day in 1983 and had to run OY then too), but they said they wanted to anyway. 1990 was a very dry winter with no snow problems (but lots of fire problems and dry water tanks), 1991 saw OY out for the first or several operations between 1991 and 1997.
This can't be the 1983 brochure as we still had boxcars on the west end of the RR until 1987(?).