in full  Oulun Lääni,  Swedish  Uleåborgs Län,  lääni (province), central Finland, bounded on the west by the Gulf of Bothnia and on the east by Russia. It has a land area of 21,956 square miles (56,866 square km). It was founded in 1776 when the former province of Ostrobothnia was replaced by the läänit (provinces) of Oulu and Vaasa. Oulu included all of Finnish Lapland until 1938, when the lääni of Lappi was created out of the northern portion. Level along the coast, the province rises in the east to forested hills; the large Oulujärvi (lake; 348 square miles [900 square km]) is situated in its south-central part. Economic activities are dominated by agriculture (mostly barley with some oats), forestry, iron mining at Otanmäki, cattle raising, and the manufacture of wood products. Principal towns are Oulu (the administrative capital), Kajaani, and Raahe. Pop. (1991 est.) 439,242.