Eastern Oregon is the eastern part of the U.S. state of Oregon. It is not an officially recognized geographic entity; thus, the boundaries of the region vary according to context. It is sometimes understood to include only the eight easternmost counties in the state; in other contexts, it includes the entire area east of the Cascade Range. Cities in the basic 8-county definition include Baker City, Burns, Hermiston, Pendleton, John Day, La Grande, and Ontario. Umatilla County is home to the largest population base in Eastern Oregon; accounting for 74% of the region's population in 2016. Hermiston, located in Umatilla County, is the largest city in the region. Major industries include transportation/warehousing, timber, agriculture, and tourism. The main transportation corridors are I-84, U.S. Route 395, U.S. Route 97, U.S. Route 26, U.S. Route 30, and U.S. Route 20. - Source: Wikipedia