[2] Umatilla County is part of the Hermiston-Pendleton, OR Micropolitan Statistical Area, which has a combined population of 94,833.

Although created to facilitate communications among local police, firemen and EMT workers who immediately respond to possible accidents or terrorist attacks on the Umatilla Chemical Depot, where the U.S. Army maintained a national arsenal of nerve gas, the network can be accessed in some places by the public for free.

Umatilla County is also located in the 29th District of the Oregon State Senate, represented by Todd Nash.

The Umatilla County Board of Commissioners is currently made up of Dan Dorran, John Shafer, and Cindy Timmons.

[18] Despite the increase in Non-affiliated voters, the Republican Party in Umatilla County has continued to see a 2:1 vote margin in Presidential elections between the years 2000 and 2024.

The gold rush of 1862 brought miners and stock raisers to the mountains and grasslands of Umatilla County.

Another stimulus was the arrival of the railroad in 1881, opening the region to the development of dry-land wheat farming.

Water for irrigation has been key to economic diversification and growth, most recently in the Hermiston area, where potatoes, onions, corn, and more than 200 other crops are grown commercially.

Low-cost power through Umatilla Electric Cooperative and good freeway access are also driving growth in the Hermiston area, with amazon.com developing large data-center operations there, and major distribution facilities for Walmart, FedEx, and UPS are all located in Hermiston.

The similarities between the areas has created a long-standing rivalry, particularly between the West-End and the Pendleton-area, with regard to economic opportunity and public resources.