Lake Puyallup

Lake Puyallup developed along the south edge of the Puget Sound Glacier. The glacier was in retreat northward after having reached its most southerly point. Drainage off the north face of Mount Rainier and the melting ice of the glacier was trapped in the valley of the Puyallup River. As the glacier moved north, the lake grew until it reached its largest capacity with the glacier at the glacial front across the Puyallup valley just south of Commencement Bay at Tacoma and northern bend of the White River at Auburn. When the ice retreated further north, it was reduced in depth and volume and takes on the name of Lake Tacoma.

The Ohop Channel
Lake Puyallup initial drain was south through the Ohop channel. The Ohop served as the drain for the Carbon and Puyallup rivers to the Nisqually. The divide between the future north-flowing rivers and the Nisqually was Lake Kapowsin at 595 ft above sea level. From Lake Kapowsin, the valley of Ohop Creek, through Ohop Lake to the Nisqually. The pass between the Puyallup River and Lake Kapowsin is 500 ft wide and 340 ft deep. At Eatonville, it is 200 ft deep and perhaps 2000 ft wide. Between the pass and Eatonville, the valley descends about 14 ft to the mile (0.6 km). Beyond Eatonville the grade is about 10 ft to the mile (0.6 km). The west side of the Puyallup trough stands about 550 ft above sea level south of Orting to a 3 miles north. West of this was the low land draining towards Lake Russell, thus blocking this westward drain. This remained the outflow until the glacier retreated further north, opening a new lower channel at Clover Creek.