HomeMy WebLinkAboutRR-42 JeffersonTwanaWayGeologyMapThe DNR 1:24,000 map does not indicate any landslides on Twana Way. There are mapped
landslides along portions of the shoreline bluff west of Twana Way. The DNR mapping is
consistent with our observations along Twana Way in that no landslide areas were identified.
The Geologic Map of the Quilcene 7.5 Minute Quadrangle, Jefferson County, Washington
(Contreras and others, 2014) (DNR) with approximate location of Twana Way marked as blue
dashed line. Qb = beach deposits, Qgic = ice contact deposits, Qcw = Whidbey Formation, Qgdp
= Possession glacial rift, Qco = Olympia non-glacial deposits, Qgdd = Double Bluff glacial drift,
Qc = Pre-Fraser non-glacial deposits, Qls = landslide. Hachures are landslide scarps. Heavy
dotted line with query is a surmised potential fault.
Qcw
RR-42 – CA received 8/22/25, Exhibit 42
The DNR geology information portal includes mapped landslides. The DNR has not mapped any
landslides along Twana Way. The DNR mapping is consistent with our observations of no
landslides on the slopes along Twana Way.
DNR geologic portal with mapped landslide shown with purple shading.
Dan McShane, L.E.G., M.Sc.
Licensed Engineering Geologist
RR-42 – CA received 8/22/25, Exhibit 42