Concurrently the upper river valley north of the glacial lake area, was covered by ice by the Cordilleran ice sheets Okanogan lobe, which produced the topography seen in the Republic area today. At maximum extent, the lobe sent the Sanpoil sublobe down the upper Sanpoil river valley to a point somewhere between Empire Creek and Manila Creek. It has been suggested that Glacial Lake Columbia maintained a highstand for up to two centuries at about 15,350 14C yr BP.
At the same time, the region north of the glacial lake was covered by ice from the Cordilleran ice sheets Okanogan lobe, resulting in the current topography in the Republic area. At its peak, the lobe sent the Sanpoil sublobe down the upper Sanpoil river valley to a point between Empire Creek and Manila Creek. It is suggested that Glacial Lake Columbia remained at high water levels for up to two centuries around 15,350 years ago.