OK...You need my ethos for this because I lived in Cheney for 3 years. My motorhome is stored there and 2 of my kids go to school there.

Rare for EQ's but always a possibility. I would expand your radius by 40KM covering Spokane. I mean if it were my forecast which it isn't.

Lots of quakes west of Cheney....Cheney is on top of many cubes of vocanic rock. You cannot walk 1/4 mile without finding a standing piece of cooled lava. Cheney was always a small town with the Eastern Washington University being the center..It was a small school...and in todays standards it still is small.....Cheney started growing quite a bit in 1998. A number of gated communities...Even a Taco Bell:-)...The area was heavily covered by volcanic ash when St Helens went up. Some cars in the area still have dual filter systems above the hood.

Had a good friend who lived in Cheney...friend and neighbor to the mayor. He was golfing in Spokane when St Helens blew and he and his friends actually heard it! By the time they got home the ash was laready falling....

So theres my two cents too!
Bob