Emergency services were called to the former Mount Lambie service station site on the Great Western Highway about 5am on Tuesday following reports a truck driver had been shot.

Police were told that the truck driver, a 42-year-old man from Western Australian, had been sleeping in the vehicle when a group of unknown men forced entry to the cabin.

The men assaulted the truck driver, dragged him from the vehicle and shot him twice in his right upper thigh and right foot.

The group then stole personal items from the truck before fleeing the area.

The truck driver was treated at the scene by paramedics before being taken to Lithgow Hospital. He was then airlifted to Westmead Hospital where he underwent surgery and remains in a stable condition.

Chifley Police District officers attended and established crime scenes on the Great Western Highway at Mount Lambie and at the intersection of Wallerawang and Rydal Road.

Detectives from the State Crime Command's criminal groups squad have taken over the investigation under Strike Force Hathern.

Squad commander, Detective Superintendent Robert Critchlow, said police were seeking assistance from the community to identify those involved in the shooting.

"As investigations continue, police are appealing for anyone in the community that may have been travelling along the Great Western Highway between 8pm on Monday and 5am on Tuesday, to please come forward," he said.

"We are specifically seeking dashcam footage from any vehicles that were in the area at the time and may have vital information about those involved.

"The injuries this man sustained from the assault and the shooting were significant and given the location he was left in, he is lucky to be alive."

Investigations into the attack are continuing.