Police believe the driver of the low-loader truck, which was thought to be carrying a green tractor, may have witnessed the crash or been near the intersection of Shades Creek Road and Euchareena Road in Molong when the two cars collided about 5pm on Tuesday.

L-plater Sevanah Lang, 16, and her mother Kelly Landers, 39, were killed when their vehicle and a Subaru Outback collided at the T-intersection.

Sevanah was behind the wheel of the Ford Laser with her mother in the passenger's seat when the crash occurred.

A woman, her newborn baby and one-year-old child in the other vehicle were not injured.

Sevanah and Ms Landers lived in Molong, where Sevanah attended Molong Central School. Ms Landers is believed to have been engaged to be married.

Inspector Bruce Grassick, from the Canobolas Local Area Command, appealed for the driver of the truck to come forward.

"It is a Kenworth low-loader, and it appears to have been [carrying] a green tractor," he said.

"We don't know the identity of the driver and we're hoping for that person to make contact with us and assist us."

Friends returned to the scene of the crash on Wednesday to lay flowers and pay tribute to the mother and daughter, who were well-known in the area.

Cabonne Shire mayor Michael Hayes told the Central Western Daily that the residents of Molong, about 35 kilometres north-west of Orange, had been devastated by the tragedy.

"To see a local mother and a 16-year-old girl with her whole life ahead of her die in this way is heartbreaking," Cr Hayes said.

"In close-knit communities like ours, I am certain many people will know the family and will feel this loss terribly.

"Our thoughts are with the family and friends and also with the Molong Central School community, where I'm sure students and their teachers will be supporting each other as they try to come to terms with this tragic loss."

Among those who visited the crash site on Wednesday were family friends Laura McCumstie and Connie and Michael Beletic.

Connie described Sevanah as a "beautiful and caring person", while Laura said she was "really bright and happy".

Mr Beletic was also deeply saddened.

"I knew them pretty well, we came down to pay tribute and respect," he said.

Facebook pages have also been set up to pay tribute to the mother and daughter.

Inspector Grassick said police had seized both vehicles involved in the crash, and police were preparing a report for the coroner.

With the Central Western Daily