Okanogan
Country Geology
(or How
the Okanogan grew)
Glen and Elizabeth Widel photo
Gneiss (or mylonite) exposed just north of
Riverside. The rock has been altered from an earlier
form, probably sedimentary, with new hot solutions
added and then tremendous pressure applied so that
it gets plastic and its crystals reform. Sometimes
the formation even indicates the direction in which
the pressure operated.
