 Ramba uchiverenga ndima iyi - Hofisi yeposvo yokutanga yeUmatilla yakatangwa muna September 1851 paUmatilla Indian Agency nechokumabvazuva kwePendleton, asi yakamiswa kushanda muna January 1852. Umatilla Indian Reservation yakasikwa muna 1855 pashure peWalla Walla Councilchibvumirano uye vazhinji vemadzinza eUmatilla, Cayuse neWalla Walla vakatamira ikoko, nechikamu chikuru chenyika dzavo chichipiwa kuhurumende yeU.S. Pasina nguva refu pashure pacho, apo ndarama yakawanwa muBoise Basin yeIdaho uye muMontana muna 1862, Rwizi rweColumbia rwakava nzira inokosha yokuenda kuminda yendarama. Gore iroro Timothy K. Davenport akaongorora nzvimbo yeguta pamuromo weRwizi rweUmatilla ndokunyorera plat muna 1863. Nzvimbo yacho yakasarudzwa nokuda kwenzvimbo yayo iri pasi peUmatilla Rapids, iyo yakaumba musoro wemvura yokufambisa paColumbia uye yakadzivisa zvikepe kubva pakufamba mberi kumusoro kwemvura pasina kudikanwa kuti zvifambiswe kana kuti zvinoda kuti mutoro wavo uendeswe kuchikepe chitsva pamusoro pemvura. Nzvimbo yacho yakatanga kuzivikanwa seUmatilla Landing, ipapo Guta reUmatilla, ipapo Columbia, ipapo Guta reUmatilla zvakare mukati megore rinotevera kana kupfuura. Hofisi yayo yeposvo yakatangwa muna 1863 naZ. F. Moody somukuru weposvo. 