Hi Jorma, in 1920 Sulo Ahola and parents were living in Port Emma, Dickey Co., North Dakota, USA. Arvid, b. Finland, 31 yrs old, immigrated in 1913, alien in 1920, farmer; Elma, b. Finland, 30, Sulo, b. ND, 5 yrs old.
In 1930 the family was living in Astoria, Clatsop County, OR. M. Arvid, b. Finland, 42, married @ 24, immigrated in 1913 & alien in 1930, laborer long shore; Sophia E., b. Finland, 41, married 23, immigrated 1913 & alien in 1930, operator steam baths; Sulo A., b. North Dakota, 15 yrs old.
The 1930 U. S. Census is the most recent one viewable to the public at this time. I'd contact the Clatsop County Gen. Soc., http://home.pacifier.com/~karenl/http://home.pacifier.com/~karenl/ for additional info about this family. Most Gen. Soc. charge a reasonable fee for research. Successful Hunting!