The Yilan River has its origins in the Da Jiaoxi Mountain and Xiao Jiaoxi Mountain, which are located on the boundary between Jiaoxi Township in Yilan County and Wulai Township in Taipei County, within the Xueshan Mountain Range. Its main tributaries are the Da Jiaoxi, Xiao Jiaoxi, and Wu Shi Xi rivers, which converge and flow sequentially through Yilan City and Zhuangwei Township. The river eventually merges with the Lanyang River near the Jia Ma Lan Bridge, close to the estuary, before flowing into the Pacific Ocean.
The river is accessible all year round, with open access throughout the day.
