| Lake Puyallup | |
| Location: | Puyallup River Pierce County, Washington |
| Coords: | 47.2237°N -122.3444°W |
| Lake Type: | Glacial lake (former) |
| Inflow: | Vashon Glacier |
| Outflow: | Ohop channel |
| Pushpin Map: | Washington |
| Basin Countries: | United States |
| Length: | 17mile |
| Width: | 9mile |
| Max-Depth: | 595feet |
| Residence Time: | less than 200 years |
| Elevation: | 350m (1,150feet) |
| Reference: | [1] |
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.[2]
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 595feet above sea level. From Lake Kapowsin, the valley of Ohop Creek, through Ohop Lake to the Nisqually.[1] The pass between the Puyallup River and Lake Kapowsin is 500feet wide and 340feet deep. At Eatonville, it is 200feet deep and perhaps 2000feet wide. Between the pass and Eatonville, the valley descends about 14feet to the mile (0.6 km). Beyond Eatonville the grade is about 10feet to the mile (0.6 km).[1] The west side of the Puyallup trough stands about 550feet above sea level south of Orting to a 3miles 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.[1]