Rodney Norman Marks of Umatilla was on his way to pick up newspaper stacks for distribution before his death near Highway 395 in Hermiston.
Marks, 59, was found slumped and unresponsive in his 2005 Chevrolet Impala at around 3 a.m. on Saturday. A passing motorist noticed the vehicle in the hillside sagebrush near milepost 2 of the highway.
Hermiston emergency medical services confirmed Marks was deceased shortly after arrival.
There were no signs of a crash. Although still investigating the official cause of Marks death, Oregon State Police say the man appears to have had a medical emergency.
The paper carrier delivered the East Oregonian and Hermiston Herald to peoples doorsteps in western Umatilla County. He also worked at PGG and Swift Trucking.
Marks had twin teenage sons and an adult daughter with his late wife of 25 years.