The Legislative Assembly created Gilliam County on February 25, 1885, from the eastern third of Wasco County because residents thought they were too far from the county seat in The Dalles. In 1899 a portion of southern Gilliam County was used to form Wheeler County. Gilliam County is bordered today by the Columbia River to the north, Wasco and Sherman Counties to the west, Morrow and Grant Counties to the east, and Crook County to the south. Gilliam County's area is now 1,223 square miles. It was named after Colonel Cornelius Gilliam who died accidentally while commanding the Oregon volunteers during the Cayuse War of 1847.
When the Legislative Assembly created Gilliam County, Alkali (now Arlington) was selected as the temporary county seat. The question of a permanent county seat was placed on general election ballots in 1886, 1888, and again in 1890 when Condon became the permanent seat of government in Gilliam County. Condon was originally known as Summit Springs which in 1884 took the name of a young lawyer from Alkali, Harvey C. Condon, nephew of the state geologist and university professor Thomas Condon.
Once the question of the location of the county seat was settled, voters in Gilliam County proved reluctant to provide a courthouse in Condon. After the county seat moved to Condon in 1890, county government operated out of a two-room house until 1903 when the county court appropriated money to construct a courthouse. This building was destroyed by a fire in 1954 resulting in heavy losses to the contents of the building including a large number of county records. The next year, the county replaced the burned structure with the present courthouse built on the same site.
Gilliam County continues to have a county court form of government. Elected officials now include two county commissioners, a county judge, district attorney, assessor, clerk, sheriff, surveyor, and treasurer.
The county's population had dropped from a high of 3,960 residents in 1920 to 1,750 in 1992. However, the 2000 population of 1915 represented a 11.53% increase from 1990.
For many years, Indians had traversed the county on well-worn trails to reach fishing, hunting, foraging, and trading areas. Many of these trails are still visible in the rangeland. The first non-native people in the area were Americans following the Oregon Trail to the Willamette Valley. In the late 19th century, new settlers arrived from the midwestern and eastern United States and Europe. Many settlers were part of the larger reverse migration of people who had originally settled in the Willamette Valley.
Gilliam County is in the heart of the Columbia Basin wheat area. Its economy is based primarily on agriculture centering on wheat, barley, and beef cattle. Apples and other irrigated crops are becoming an increasingly important part of the economy of the north end of the county. After agriculture and livestock, other principal industries of Gilliam County include tourism, hunting, and fishing.
Did You Know?
Gilliam County's western border is formed by the John Day River, named after a member of the Astor-Hunt overland party. Entrepreneur John Jacob Astor sent the party west from St. Louis in 1810 with the goal of setting up a post at the mouth of the Columbia River. Astor wanted to dominate fur trapping in the region.
The expedition became divided and widely separated. Experiencing incredible hardships, John Day's group dwindled to two people. Close to the mouth of the river that would later bear his name, Day and Ramsey Crooks were attacked by hostile Indians and robbed of everything--even their clothes. While they were soon rescued, one source claimed that Day later went insane and died in 1814.