Rock Climbing activities in Taiwan
River tracing outings are organised year-round by the local aborigines in Sanjhan from the community activity centre. The cost is around NT$2000 per person including all rental equipment. Trips take about eight hours return and start from the activity centre, usually in the early morning. You should be able to just go and join a group.
Sanjhan is just south of Taroko Park on the way back to Hualien. Heading south, turn right off Hwy 9 at the sign for Sanjhan (三棧). When you cross the bridge into the village stay right along the river. The community centre is obvious, 150m on at the end of the road on the left.
Note that technically you are supposed to apply for a police…