A second man was injured but made it 12 miles to the nearest residence to report the deadly accident.
The drama began earlier Thursday evening when the man who survived, a 35-year-old Oregon resident, met a young couple at a nearby bar, said Ed Troyer of the Pierce County Sheriff's Office.
After the three of them had been drinking together, the Oregon man told the couple he had a job driving an excavator at a logging site in the woods, so they all went there for a joyride.
Sgt. Trent Stevens with East Pierce Fire and Rescue said it appears the excavator was backing up with all three aboard when it tipped and rolled about 100 yards down a steep embankment.
The Oregon man either jumped or fell off the excavator as it began to tumble down the hill. But the young couple, a man and woman in their 20s, were trapped on the excavator. Both were killed instantly.
The man who survived was able to make it to the town of Wilkeson, arriving there at about 10:45 p.m. He went to a local residence to call 911 and report that he and two others had been in an accident with an excavator.
Deputies and medics from East Pierce Fire and Rescue responded to the scene. While some of the medics treated the man's injuries and took him to a trauma center, the others accompanied deputies to find the two other victims, Jaques said.
After two hours of searching up and down gravel roads, deputies and medics reached the logging site. They had to hike in the last half-mile on foot because the terrain was too rugged for a four-wheel drive vehicle.
The two victims were found dead at the scene. Crews at the scene plan to recover their bodies using a high-angle rescue.