Congregation Beth Israel of Portland, Oregon was established in 1858, before Oregon was even a state. In 1859 they built their first synagogue. That synagogue was small and modest, and was replaced in 1888 by a much larger building, which itself was destroyed by fire in 1923. Finally that synagogue was replaced by a new structure in 1928.
Through all of this, the records survive. The Family History Library has in it's collection the births and burials from 1876-1908 (FHL film #1013426 item 1). These records have now been added to the Knowles Collection - Jews of the Americas database.