Complex sentence: Immediately north of the village the Fraser Canyon begins, and the river is generally considered unnavigable past this point, although rough water is common on the Fraser anywhere upstream from Chilliwack, and even more so above Hope, about 20 miles south of Yale.
Split into simpler sentences: Immediately north of the village, the Fraser Canyon begins and the river is generally considered unnavigable past this point. Rough water is common on the Fraser anywhere upstream from Chilliwack, and even more so above Hope, about 20 miles south of Yale.