A family holiday to mark the end of summer in the US has ended in tragedy with seven people, including five children, from the same family killed in a head-on-crash in eastern Oregon.

The Washington family were headed to Las Vegas to see a family member, another relative has told Oregon local media.

Jessica Tate said his 29-year-old sister, Erika Boquet, left Lacey in Washington early Monday morning with her children Isabella, 11, Elisabeth, 8 and Tytis, 6, and another relative and their two children.

Near milepost 30 of highway Oregon 78, southeast of Burns, a 1999 Toyota 4Runner crashed into their 2016 Toyota 4Runner.

Eight people died in the head-on-collision – Ms Boquet and the other six members of her family, and the lone driver in the other car.

The Oregon State Police have identified the other three people travelling with the Boquet’s as Kyla Maria Brown, 28, of Olympia, Arianna, Marie Brown, 10 and Xavier King Johnson, 2.

The driver of the other SUV has been identified as Mark Robert Rundell, 48, of Prairie City.

Tate told Oregon local media her family was devastated by the fatal accident.

Frank Williams, Erika Boquet’s grandfather, told CNN: "She`s a beautiful person with three beautiful kids she was raising. She was doing all she could to raise not only her kids but help the entire community of Tacoma."

Oregon State Police continue to investigate the crash but have said the driver travelling alone veered into oncoming traffic while heading west, colliding with the other vehicle.