Girl, 4, dies in central NSW crash

A four-year-old girl has died after the car she was in hit a tree in central NSW.

A 30-year-old woman was driving along Mendooran Road north of Dubbo at lunchtime on Saturday when her car veered onto the wrong side of the road and hit a tree.

Her four-year-old-daughter, who was in a booster seat in the rear of the car, died at the scene, police say.

The woman was taken to Dubbo Base Hospital for treatment to a back injury.

Investigators are appealing for anyone who may have witnessed the crash to contact Crime Stoppers.

Meanwhile, a 23-year-old man has died in a motorcycle crash in the state's mid-north coast.

Police say the man and three of his friends were riding on a trail into the Woolgoolga State Forest about 8.30am (AEDT) on Saturday when they became separated.

A short time later, the 23-year-old rode over a speed hump, lost control of his bike and crashed into a tree.

After a few minutes, his friends found him and gave him CPR until paramedics arrived but he died at the scene.