So be prepared and wear warmer clothing.
Was already mentally prepared that it won't be as impressive as Jiuzhaigou so wasn't disappointed.
Visited 3rd week of Oct and there's snow accumlated esp. towards the higher parts. Since water is frozen at this time, no running water for the restrooms, so bring along your hand sanitizer.
I think it is not worth the entrance fee of CNY200 (add another CNY80 for the cable car ride up), but since we came all the way to Jiuzhaigou, we visited anyway.
The road trip to Huanglong is very scenic though, compared to going to Jiuzhaigou. Snow capped mountains and yaks along the way. May be even nicer than the Huanglong Scenic Valley. Some scenic lookouts on the way but there is not enough for the tourists - many cars and buses parked along the windy road. On our way back from Huanglong to Jiuzhaigou there are fewer pple on the scenic lookouts so you may want to consider stopping on the way back instead.
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