Two men set up a rifle with a telescopic lens before firing on a Batemans Bay firefighter, his colleague and two US Forest Service personnel patrolling in remote Washington state near the White Pass ski area, according to staggering new details contained in a debrief note prepared about the incident.
Written by US Forest Service officers, the note shows the incident began at around 1.30pm on August 23, when the first shots were heard, and only ended at 6pm after the firefighters had been rescued.
"The incident personnel watched with binoculars as one of the two individuals put a scoped rifle on a bi-pod and looked up the mountain toward them," it reads.
"They continued to wave until a shot was fired ... they then bailed off the backside of the mountain to take cover as a second shot rang out."
Fairfax Media on Tuesday revealed NSW Rural Fire Service volunteer Daniel Barwick, who last year was awarded a National Medal for protecting the Lake George area near Canberra, was one of the two Australians involved in the incident.
Fire & Rescue NSW on Tuesday confirmed one of its officers, Inspector Phillip Eberle from Batemans Bay, was the other involved.
"Support was provided to the firefighters following the incident," a spokesman said.
"We are proud of the work Australian firefighters did to help protect communities affected by these devastating wildfires and we were pleased to see them arrive home safely on Saturday."
One of the US Forest Service officers reported seeing two butchered marmots on his way to the evacuation point, along with three shell casings.
"At approximately 1500, four incident personnel spot two individuals walking down the (Pacific Coast Trail) approximately 200 yards [180 metres] below them," the note reads.
"The incident personnel stand up and holler and wave. All four are wearing yellow Nomex fire shirts. Two had bright yellow hardhats. They therefore thought they had been seen by these two individuals."
The four removed their yellow firefighting uniforms to make themselves less visible.
The US Agriculture Department Forest Service's Law Enforcement & Investigations officers and the sheriff’s departments from Lewis and Yakima counties investigated the incident.
"Two men were located inside the fire area closure ... they were shooting ground squirrels/marmots and reportedly bear hunting," the Forest Service said in a statement.
"They were issued Violation Notices by USDA Forest Service Law Enforcement Officers for violation of the closure order."
Additional charges are also pending.
A spokeswoman confirmed the debrief note, prepared by Tom Johnston and Arley Paulus, was a document prepared by the Forest Service.
The FBI said it was aware of the alleged incident, but was not involved in the investigation.
Nearly 80 Australian firefighters have been working with the US Forest Service and Bureau of Land Management in northern California, Oregon and Washington since July, and were dispatched to the popular White Pass ski destination in August after fire spread across the area.
All Australian crews returned over the weekend.