When I vsited, I entered the Park through the northernmost gate, in the town of Mt. Morris. I drove down the Park drive until a point maybe 20-25% through the park, when I had to stop and exit, because the Park drive from there to a point roughly halfway down was closed. They keep it unplowed in the winter and folks can cross-country ski. I luckily ran into someone who was about to set off, and he informed me that I could re-enter the park down by the town of Castile and then I could continue to the falls from there.
After I did re-enter the park, this was the first opportunity to pull over and see the river gorge — an overlook opposite what is called Archery Field. I guess you can shoot arrows there, but at about 25° before wind chill nobody was doing any such thing.