Oregon Department of Geology and Mineral Industries (DOGAMI) has released it's new landslide maps of the Canby quadrangle: IMS-29 includes the southwest area of West Linn.
Geodetic Survey Stations in West Linn: there are two NGS survey stations available in West Linn: SALAMO and SHEPHERD. Also contact Clackamas County Surveyor for more information on surveys in West Linn.