Complex sentence: Named tributaries from source to mouth are the North Fork Calapooya Creek, South Fork Calapooya Creek, then White, Coon, Timothy, Buzzard Roost, Cooper, and Filler creeks.
Split into simpler sentences: Named tributaries from source to mouth are the North Fork Calapooya Creek and South Fork Calapooya Creek. Then come White, Coon, Timothy, Buzzard Roost, Cooper, and Filler creeks.