I visited Shiretoko in October 2008. We went to see the fall foliage, which was beautiful. One thing to keep in mind is that Hokkaido is very cold starting in early October and many of the sites in Shiretoko are closed starting in the end of September. We only saw the sites close to the visitor center and along the roads in the park. The weather was rainy and cloudy and a lot of mist covered the mountains. It made the scenery very dramatic and showed the raw nature of the park. Of course so did watching for deer and bears on the road as we drove through rain and snow up at the top of the mountain pass. I plan on going back this summer so that I can enjoy another aspect of this fantastic place.