The Chiwaukum area on the eastern flank of the Cascade Range of Washington State is a type locality for a clastic basin in what is, broadly speaking, a continental arc province. Evans (1994) concluded that the Eocene Chumstick Formation was deposited syntectonically in the Chiwaukum graben in a regional extensional or transtensional environment. In contrast, we (Cheney and Hayman, 2009a) recognized that, with the exception of a period of strike-slip faulting in the late Eocene–Oligocene, the region has experienced several episodes of compression. We welcome Evans's (2010) comments on our work because they can motivate tests of these...

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