There’s no direct bus from Dujiangyan to Huanglongxi—transfers are needed. Recommended options: High-speed train + scenic area direct bus: Take the high-speed train from Dujiangyan to Chengdu (30 mins, 10 RMB), then transfer to the direct bus departing at 7:30 from Exit C of Jinsha Site Museum, arriving at Huanglongxi’s back mountain (2 hrs, 35 RMB). Total cost: 45 RMB, total time: 3.5 hrs. Coach bus transfer: Take a coach from Dujiangyan to Chengdu Chadianzi Bus Station (1.5 hrs, 20 RMB), then transfer to direct buses at 9:00/9:30 (2.5 hrs, 33 RMB). Total cost: 53 RMB, total time: 4 hrs.