 Ramba uchinyora ndima iyi - U.S. Geological Survey USGS inoshandisa zviyereso zvishanu zvetsime parwizi, paHarrisburg, Corvallis, Albany, Salem, uye Portland. Avhareji yokubuda kwemvura pabhiriji rakadzika zvikuru, pedyo neMorrison Bridge muPortland, yaiva pakati pa1972 na2013. Riri paRwizi rwemakiromita RK 20.6, rwizi rwemakiromita RM 12.8, rwizi rwemakiromita RK 20.6, rwizi rwemakiromita RM 12.8 kana kuti rwizi rwemakiromita RK 20.6, rwizi rwemakiromita RK 20.6, rwizi rwemakiromita RM 12.8 kana kuti rwizi rwemakiromita RK 20.6, rwizi rwemakiromita RM 12.8 kana kuti rwizi rwemakiromita RK 20.6, rwizi rwemakiromita RM 12.8 kana kuti rwizi rwemakiromita RK 20.6, rwizi rwemakiromita RM 12.8 kana kuti rwizi rwemakiromita RK 20.6. Kuyerera kukuru kwakanyorwa panhepfenyuro iyi kwakanga kuri pana February 9, 1996, mukati meMafashamo eWillamette Valley a1996, uye kuderera kwakanga kuri pana July 10, 1978. Kuyerera kukuru kwakanyorwa kweWillamette pane imwe nzira yakasiyana muPortland kwakaitika panguva yemafashamo muna 1861. Uku nokumwe kuyerera kukuru kwakawanda kwakatangira Mutemo Wokudzora Mafashamo wa1936 uye kuvakwa kwedhamu pamativi makuru erwizi rwaWillamette. 