[x1stcav]

Good point, and appreciated, as I was a geography/geology major.

[steve86]

I am born, raised and living in the Columbia Basin of Washington State which has been quiet geologically for a while also (notwithstanding certain Cascade volcanoes which tend to dump a lot of ash here). But you never know when basin activity will pick up (geology and weather).

There were periods of quiescence between major extrusive events...The flows were extruded from vents and northwest-trending fissures east of Pasco and in the southeast corner of the state... The flows were extremely fluid, and as a result a number of them reached the Pacific Ocean via the ancestral Columbia River drainage...The Columbia Basin was the scene of the greatest catastrophic floods ever documented in the geologic record. The Pleistocene Cordilleran ice sheet advanced south into Idaho, damming the Clark Fork River at the Montana border. A huge impoundment, called Lake Missoula, formed.

(later it let go).