These plates were used on big trucks and rigs from the 1920's to 2001. Any truck that had the possibility of traveling through Oregon needed one of these plates, so they were on a large number of trucks.
Late 1920s	1933	1930s
1940s ?? White on Green	1940s ?? Black on Orange	1940s ?? White on Blue
1940s ?? Black on Yellow	1940s ?? White on Black	1947
1956-57	1958-59	1960-61
1962-63	1964-65	1966-67
1968-69	1970-71	1972-73
1974-75	1976-77	1978-79 Die Variation 1
1978-79 Die Variation 2	1980-81	1982-83
1984-85	1986-87 TYPE 2	1988-89 TYPE 1
1988-89 TYPE 2	1988-89 TYPE 1	1990-91
1992-93	1993	1994
1995	1996	1997
During the 1997 issue, the legend changed to "D.O.T."
1997	1998	1999
2000	2001	TRUSTED CARRIER
These plates were no longer required after 2001. The "TRUSTED CARRIER" plates came into use at this point.