A 14-year-old boy has died after a trail bike accident in the NSW central tablelands yesterday.

The boy and his two brothers, one older and one younger, left a campsite and went riding on Cupitts Lane, a dirt road in Sunny Corner State Forest near Bathurst, about 9am, police said.

But he was separated from his brothers during the ride, police said.

The boy's brothers noticed he was missing when they returned to the campsite, where they were camping with family members, about 9.40am.

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The boy's father started a search for him. About 45 minutes later, the father found his son off the dirt road.

Emergency services were called but he was pronounced dead.

It appeared he lost control of his bike, police said. Police did not say what injuries the boy sustained.

Inspector Mitch Aldridge of Chifley Local Area Command said it was common for children to ride trail bikes in Sunny Corner State Forest.

"It's all log-trucking trails. There's good roads. It's very common for trail bikes to use these roads," he said.

"There are no other vehicles on them except when trucks are picking up trees and at the moment they are not doing that."

He added that the weather in the area was fine yesterday.

A report will be prepared for the coroner.

Read the latest updates at the Western Advocate.