Sam Woodhead will be taken to Longreach Base Hospital for a medical assessment, Queensland Police said.
The teenager's sister wrote on Facebook: "We have been told that they have found Sam!! We have no information on his condition or where he was found yet, so keep your fingers crossed."
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Long-awaited A-level results will be received by teenagers on Thursday, the first to do so following major reforms of the system in England.
Theresa May will today announce details of a new mental health awareness course designed to help struggling teenagers.
A-level results will be on Thursday, but what should you do if your results are not quite what you had hoped for?