The following events occurred before 1 AD:
c. 1,000,000,000 BC Edit
c. 200,000,000 BC Edit
c. 100,000,000 BC Edit
- The subcontinent Okananga collides with North America, resulting in the formation of White Tail Peak and Blue Pine Mountain, as well as the Kootenay Arc in the western part of Twin Peaks.
1,000,000 BC to 500,000 BC Edit
- Washington is under ice a mile thick. The melting ice results in the creation of White Tail Falls and several valleys and gorges near the Pearl Lakes.
c. 25,000 BC Edit
- Ancestors to the Snoqualmie, Umpqua, Methow, Cayuse, Yakima, Spokane, Flathead, and Nez Perce tribes arrive in Washington from Asia.