If there was a NOTAM out before the accident it is surprising that ATC didn't ask the pilots if they had it. I recently flew into an airport with a PPR NOTAM (twice), and ATC asked both times if we had that particular NOTAM. In fact it was Denver Center, who would also have been working the flight into Telluride.
My thoughts too..
Hard to believe center gave them an approach to NOTAM'ed closed runway..