Eugene B. Contreras was born 21 Mar 1897 in Stockton, CA to John Garcia & Mary Ellen [Sullivan] Contreras. His father was the descendant of Mexican residents of California and his mother Irish immigrants. Eugene was one of 7 children born to the couple. His father worked at the Stockton Woolen Mill at the time of his birth. 

By 1910 the family had moved to St. Johns, OR along with his Uncle Frank and Aunt Pastora [Fimby] Contreras. They joined the workforce of the newly opened Portland Woolen Mill. They remained there for a few years and then went to Salem, OR to work at the Thomas Kay Woolen Mill. 

Eugene had an 8th grade education before joining his father, uncle and brother at TKWM. He worked in the carding department. In 1917 when he registered for the draft, he was granted exemption for his war-time factory work. His draft card lists his employer as Oregon City Mill. In 1920, his father John died, a victim of type 2 diabetes. Brother Eugene and Joseph moved back into the family home to financially support their mother and younger siblings.  

By 1929 Joseph and Eugene had moved to 1669 E. 16th St. in Portland and taken work at the Oregon Worsted Mill. Eugene continued to work at the mill until his death 12 Apr 1958 in Portland. He never married. He was buried in Lincoln Memorial Park in Portland, OR. 

1917 Contreras Eugene, hlpr T K W M Co, res 434 S 16th 

1921 Contreras Eug carder, r 625 Umatilla av (Portland) 

1929 Contreras Eug lab r1669 E 16th (Portland) 

1930 Contreras Eug B oiler, OWCo r1669 E 16th (Portland) 

1933 Contreras Eug B, textilewkr OWCo r1669 E 16th (Portland) 

1953 Contreras Eug B, oiler Oregon Worsted, r 1006 SE Harney (Portland) 

1910  Eugene B. Contreras Age: 13. Birth Date: 1897 in California. Home in 1910: 1031 Hayes St. St. Johns Ward 2, Multnomah, OR. Single, son to HOH. Additional household members: John Contreras, age 36 (father), Mary E. Contreras, age 31 (mother), Joseph L. Contreras, age 11 (brother), Margaret W. Contreras, age 8 (sister), John L. Contreras, age 6 (brother), Albert S. Contreras, age 5 (brother), Laurence G. Contreras, age 0 (brother), Kote Winters, age 37 (lodger). 

1920  Eugene B. Contreras Age: 22. Birth Year: 1898 in California. Home in 1920: 625 Umatilla Ave. Portland, Multnomah, OR. Single, son to HOH. Occupation: Laborer in Woolen Mill. Additional household members: John Contreras, age 47 (father), Mary E. Contreras, age 41 (mother), Joseph L. Contreras, age 20 (brother), Winifred M. Contreras, age 17 (sister), John L. Contreras, age 15 (brother), Albert S. Contreras, age 13 (brother), Laurence G. Contreras, age 10 (brother), Norbert R. Contreras, age 5 (brother). 

1930  Eugene B. Contreras Age: 32. Birth Year: abt 1898 in California. Home in 1930: 1669 E. 16th St. S. Portland, Multnomah, OR. Single, son to HOH. Occupation: Mechanic in Woolen Mill. Additional household members: Mary E. Contreras, age 51 (mother), Joseph Contreras, age 31 (brother), John Contreras, age 26 (brother), Lawrence Contreras, age 20 (brother), Norbert Contreras, age 15 (brother). 

1940  Eugene B. Contreras Age: 43. Birth Year: abt 1897 in California. Home in 1940: 1734 Spokane St. Portland, Multnomah, OR. Single, son to HOH. Occupation: Textile Worker in Oregon Worsted Mill. Additional household members: Mary E. Contreras, age 61 (mother), Joseph L. Contreras, age 41 (brother). 

1950  Eugene B. Contreras Age: 53. Birth Date: abt 1897 in California. Home in 1950: Portland, Multnomah, OR. Single, son to HOH. Occupation: Maintenance Man in Woolen Mill. Additional household members: Mary C. Contreras, age 71 (mother), Joseph L. Contreras, age 51 (brother).