Complex sentence: The Kobuk River is a periglacial river, fed by a remnant glacial lake (Walker Lake) and mountain snowmelt in the Brooks Range, cutting a channel through a landscape otherwise dominated by permafrost.
Split into simpler sentences: The Kobuk River is a periglacial river, fed by a remnant glacial lake (Walker Lake) and mountain snowmelt in the Brooks Range. It cuts a channel through a landscape otherwise dominated by permafrost.