Waitt (1979) identified three faults cutting across the Kittatas Valley. While the faults do off set Pleistocene sediments of the Thorpe Gravel, no definitive off sets have been identified within younger (last 11,000 years) sediments. The off set of the Thorp Gravel alluvial plain north of Ellensburg can readily be seen in the DEM:
Fault off set is an east-west fault cutting across the center of the DEM with up to the south
This DEM has the fault marked in black
There are two other faults. One is closer to Ellensburg and the other towards the north.
The aerial view of the the fault shown above via Google earth: