| Quaternary fragmental volcanic rocks and deposits (includes lahars) |
| Quaternary alluvium |
| Quaternary mass-wasting deposits |
| Pleistocene continental glacial drift |
| Holocene alpine glacial drift |
| Pleistocene alpine glacial drift |
| Quaternary volcanic rocks |
| Pleistocene volcanic rocks |
| Pleistocene intrusive rocks |
| Quaternary-Tertiary volcanic rocks |
| Quaternary-Tertiary intrusive rocks |
| Tertiary sedimentary rocks and deposits |
| Tertiary fragmental volcanic rocks and deposits (includes lahars) |
| Tertiary volcanic rocks |
| Miocene Columbia River Basalt Group, Grande Ronde Basalt |
| Eocene Crescent Formation, volcanic rocks |
| Tertiary intrusive rocks |
| Tertiary heterogeneous metamorphic rocks |
| Mesozoic sedimentary rocks and deposits |
| Water |
| Ice |
