Union County is one of the 36 counties in the U.S. state of Oregon, and one of the 8 counties of eastern Oregon. As of the 2020 census, the population was 26,196. The county comprises the La Grande micropolitan statistical area and the county seat is La Grande.
History
According to Oregon Geographic Names, the county is named for the town of Union. Union County was originally part of Baker County (which was originally a part of Wasco County, which was originally part of Clackamas County). The northern end of the Grande Ronde Valley was the first part to be settled. During the 1860s, population growth in eastern Oregon prompted the State Legislature to split Umatilla and Baker Counties from Wasco County in 1862. Further settlement in the Grande Ronde Valley led to the division of Baker County to create Union County on October 14, 1864. The county doubled in population between 1880 and 1890. The Forest Service owns 47% of the land in the county.
Adjacent counties
- Umatilla County (northwest)
- Wallowa County (northeast)
- Baker County (southeast)
- Grant County (southwest)