It is Jiuzhaigou. October is all fine. But the first week is the National Day Holiday, a 7-day holiday. so, very crowded at that time. I guess you can go later that month. The temperature is about 5-15 degrees. A bit cold. Prepare downcoat. October 15-25 is the most beautiful time for the red leaves. Not rainy. As to delicacy, you can try dried yak meat, traditional highland barley wine and Tibetan butter tea. souveniers, you can buy Qiang ethnic minority's emboidery, Tibetain ornaments, like tibetan silver, tibetan knives. Tibetain is a kind of mixed silver, not pure. If it is too expensive, don't buy it. Knives are not allowed to carry to airplane, so don't buy it too. Tibetan herbal medicine is special but not suggesed too. There are several theater at different level having Tibetan songs and dance show. You should pay for them.