| Province | Rock Unit | Rock Type | Age | Description |
| Coast Range and Klamath Mountains | Qal | Alluvial deposits | Holocene | Sand, gravel, and silt forming flood plains and filling channels of present streams. In places includes talus and slope wash. Locally includes soils containing abundant organic material and thin peat beds. |
| Cascade Range | Qal | Alluvial deposits | Holocene | Sand, gravel, and silt forming flood plains and filling channels of present streams. In places includes talus and slope wash. Locally includes soils containing abundant organic material, and thin peat beds. |
| Eastern Oregon | Qal | Alluvial deposits | Holocene | Sand, gravel, and silt forming flood plains and filling channels of present streams. In places includes talus and slope wash. Locally includes unconsolidated sediment marginal to playas, soils containing abundant organic material, and thin peat beds. |