Jiuzhaigou is also very easy to travel. just imagine a Y shape, that is what the route is . If you have only one day, I would recommend enter the park early ( 7 am ), take the bus all the way to the final stop of right side of the Y, and then travel down enjoying all the best part of Juizhaigou park. You can take hop-on hop-off buses from scenic spot to scenic spot. They come every few minutes. The visit will take easily whole day.